Mon, 17 Apr 2023 16:20:58 +0200
Version 0.4.1 Measure internal chip temperature, range -10 to 80. Result available in mqtt json payload.
1
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
1 | # Driver for the ams CCS811 digital gas sensor for monitoring indoor air quality |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
2 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
3 | The driver is for the usage with the ESP-IDF. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
4 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
5 | ## About the sensor |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
6 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
7 | The CCS811 is an ultra-low power digital sensor which detects |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
8 | **Volatile Organic Compounds (VOC)** for Indoor Air Quality (IAQ) monitoring |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
9 | that. The sensor allows to |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
10 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
11 | - convert raw sensor data to Total Volatile Organic Compound (TVOC) and |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
12 | equivalent CO2 (eCO2), |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
13 | - compensate gas readings due to temperature and humidity using an external |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
14 | sensor, |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
15 | - trigger interrupts when new measurement results are available or eCO2 value |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
16 | exceeds thresholds, |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
17 | - correct baseline automatically or manually |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
18 | - connect a NTC thermistor to provide means of calculating the local ambient |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
19 | temperature. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
20 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
21 | The sensor uses an I2C interface and supports clock stretching. See the notes |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
22 | on clock stretching during I2C interface intialization. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
23 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
24 | ## Measurement Process |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
25 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
26 | ### Sensor modes |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
27 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
28 | The CCS811 can operate in 5 different modes: |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
29 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
30 | Mode | Driver symbol | Period | RAW data | IAQ values |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
31 | ---- | ------------- | ------ |:--------:|:----------: |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
32 | Idle, Low Current Mode | `CCS811_MODE_IDLE` | - | - | - |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
33 | Constant Power Mode | `CCS811_MODE_1S` | 1 s | X | X |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
34 | Pulse Heating Mode | `CCS811_MODE_10S` | 10 s | X | X |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
35 | Low Power Pulse Heating Mode | `CCS811_MODE_60S` | 60 s | X | X |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
36 | Constant Power Mode | `CCS811_MODE_250MS` | 250 ms | X | - |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
37 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
38 | After power up, the sensor starts automatically in *Idle, Low Current Mode* |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
39 | (`CCS811_MODE_IDLE`). To start periodic measurements, the mode of the sensor |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
40 | has to be changed to any measurement mode. Measurement modes with with |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
41 | different rates of periodic measurements are available, see table above. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
42 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
43 | **Please note:** In *Constant Power Mode* with measurements every 250 ms |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
44 | (`CCS811_MODE_250MS`) only raw data are available. In all other measurement |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
45 | modes, the Indoor Air Quality (IAQ) values are available additionally. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
46 | The *Constant Power Mode* with measurements every 250 ms (`CCS811_MODE_250ms`) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
47 | is only intended for systems where an external host system wants to run an |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
48 | algorithm with raw data. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
49 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
50 | Once the sensor is initialized with function `ccs811_init()`, function |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
51 | `ccs811_set_mode()` can be used to start periodic measurements with a given |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
52 | period. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
53 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
54 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
55 | ESP_ERROR_CHECK(i2cdev_init()); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
56 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
57 | static ccs811_dev_t sensor; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
58 | memset(&sensor, 0, sizeof(ccs811_dev_t)); // Zero descriptor |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
59 | ESP_ERROR_CHECK(ccs811_init_desc(&sensor, 0, CCS811_I2C_ADDRESS_1, 5, 4); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
60 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
61 | if (ccs811_init(&sensor) == ESP_OK) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
62 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
63 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
64 | // start periodic measurement with one measurement per second |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
65 | ESP_ERROR_CHECK(ccs811_set_mode(&sensor, CCS811_MODE_1S)); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
66 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
67 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
68 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
69 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
70 | **Please note:** |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
71 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
72 | 1. After setting the mode, the sensor is in conditioning period that needs up |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
73 | to 20 minutes, before accurate readings are generated, see the data sheet for |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
74 | more details. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
75 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
76 | 2. During the early-live (burn-in) period, the CCS811 sensor should run for |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
77 | 48 hours in the selected mode of operation to ensure sensor performance is |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
78 | stable, see the datasheet for more details. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
79 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
80 | 3. When the sensor operating mode is changed to a new mode with a lower sample |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
81 | rate, e.g., from *Pulse Heating Mode* (`CCS811_MODE_10S`) to *Low Power Pulse |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
82 | Heating Mode* (`CCS811_MODE_60S`), it should be placed in *Idle, Low Current |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
83 | Mode* (`CCS811_MODE_IDLE`) for at least 10 minutes before enabling the new |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
84 | mode. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
85 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
86 | When a sensor operating mode is changed to a new mode with a higher sample |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
87 | rate, e.g., from *Low Power Pulse Heating Mode* (`CCS811_MODE_60S`) to |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
88 | *Pulse Heating Mode* (`CCS811_MODE_10S`), there is no requirement to wait |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
89 | before enabling the new mode. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
90 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
91 | ## Measurement results |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
92 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
93 | Once the measurement mode is set, the user task can use function |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
94 | `ccs811_get_results()` with same rate as the measurement rate to fetch the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
95 | results. The function returns **raw data** as well as **Indoor Air Quality |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
96 | (IAQ)** values. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
97 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
98 | While raw data represents simply the current through the sensor and the voltage |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
99 | across the sensor with the selected current, IAQ values are the results of the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
100 | processing these raw data by the sensor. IAQ values consist of the **equivalent |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
101 | CO2 (eCO2)** with a range from 400 ppm to 8192 ppm and **Total Volatile Organic |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
102 | Compound (TVOC)** with a range from 0 ppb to 1187 ppb. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
103 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
104 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
105 | uint16_t iaq_tvoc; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
106 | uint16_t iaq_eco2; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
107 | uint8_t raw_i; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
108 | uint16_t raw_v; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
109 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
110 | // get the results and do something with them |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
111 | if (ccs811_get_results(&sensor, &tvoc, &eco2, &raw_i, &raw_v) == ESP_OK) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
112 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
113 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
114 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
115 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
116 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
117 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
118 | If some of the results are not needed, the corresponding pointer parameters |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
119 | can be set to NULL. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
120 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
121 | If the function `ccs811_get_results()` is called and no new data are |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
122 | available, e.g., due to the sensor mode time tolerance of 2%, the function |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
123 | still returns successfully. In this case, the results of the last measurement |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
124 | are returned and the error code CCS811_ERR_NO_NEW_DATA. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
125 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
126 | **Please note:** |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
127 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
128 | 1. In *Constant Power Mode* with measurements every 250 ms (`CCS811_MODE_250MS`) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
129 | only raw data are available. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
130 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
131 | 2. The rate of fetching data must not be greater than the rate of measurement. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
132 | Due to the sensor mode timing tolerance of 2 %, the rate of fetching data |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
133 | should be lower than the measurement rate. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
134 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
135 | 3. If the function is called and no new data are available, the results of the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
136 | latest measurement are returned and error code CCS811_ERR_NO_NEW_DATA is set. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
137 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
138 | ### Compensation |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
139 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
140 | If information about the environment like temperature and humidity are available |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
141 | from another sensor, they can be used by CCS811 to compensate gas readings due |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
142 | to temperature and humidity changes. Function `ccs811_set_environmental_data()` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
143 | can be used to set these environmental data. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
144 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
145 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
146 | float temperature; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
147 | float humidity; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
148 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
149 | if (sht3x_get_results(sht3x, &temperature, &humidity) == ESP_OK) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
150 | // set CCS811 environmental data with values fetched from SHT3x |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
151 | ccs811_set_environmental_data(ccs811, temperature, humidity); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
152 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
153 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
154 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
155 | ### NTC |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
156 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
157 | CCS811 supports an external interface for connecting a negative thermal |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
158 | coefficient thermistor (R_NTC) to provide a cost effective and power efficient |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
159 | means of calculating the local ambient temperature. The sensor measures the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
160 | voltage V_NTC across R_NTC as well as the voltage V_REF across a connected |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
161 | reference resistor (R_REF). Function `ccs811_get_ntc_resistance()` can be used |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
162 | to fetch the current resistance of R_NTC. It uses the resistance of R_REF and |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
163 | measured voltages V_REF and V_NTV with the following equation: |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
164 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
165 | ```text |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
166 | R_NTC = R_REF / V_REF * V_NTC |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
167 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
168 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
169 | Using the data sheet of the NTC, the ambient temperature can be calculated. See |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
170 | application note ams AN000372 for more details. For example, with Adafruit |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
171 | CCS811 Air Quality Sensor Breakout the ambienttemperature can be determined as |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
172 | following: |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
173 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
174 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
175 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
176 | #define CCS811_R_REF 100000 // resistance of the reference resistor |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
177 | #define CCS811_R_NTC 10000 // resistance of NTC at a reference temperature |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
178 | #define CCS811_R_NTC_TEMP 25 // reference temperature for NTC |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
179 | #define CCS811_BCONSTANT 3380 // B constant |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
180 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
181 | // get NTC resistance |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
182 | uint32_t r_ntc; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
183 | ccs811_get_ntc_resistance(&sensor, CCS811_R_REF, &r_ntc); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
184 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
185 | // calculation of temperature from application note ams AN000372 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
186 | double ntc_temp; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
187 | ntc_temp = log((double)r_ntc / CCS811_R_NTC); // 1 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
188 | ntc_temp /= CCS811_BCONSTANT; // 2 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
189 | ntc_temp += 1.0 / (CCS811_R_NTC_TEMP + 273.15); // 3 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
190 | ntc_temp = 1.0 / ntc_temp; // 4 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
191 | ntc_temp -= 273.15; // 5 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
192 | .... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
193 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
194 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
195 | ### Interrupts |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
196 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
197 | CCS811 supports two types of interrupts that can be used to fetch data: |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
198 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
199 | - data ready interrupt (INT_DATA_RDY) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
200 | - threshold interrupt (INT_THRESHOLD) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
201 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
202 | #### Data ready interrupt |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
203 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
204 | At the end of each measurement cycle (every 250 ms, 1 second, 10 seconds, or |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
205 | 60 seconds), CCS811 can optionally trigger an interrupt. The signal *nINT* is |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
206 | driven low as soon as new sensor values are ready to read. It will stop being |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
207 | driven low when sensor data are read with function `ccs811_get_results()`. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
208 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
209 | The interrupt is disabled by default. It can be enabled with function |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
210 | `ccs811_enable_interrupt()`. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
211 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
212 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
213 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
214 | // enable the data ready interrupt |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
215 | ESP_ERROR_CHECK(ccs811_enable_interrupt(&sensor, true)); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
216 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
217 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
218 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
219 | #### Threshold interrupt |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
220 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
221 | The user task can choose that the data ready interrupt is not generated every |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
222 | time when new sensor values become ready but only if the eCO2 value moves from |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
223 | the current range (LOW, MEDIUM, or HIGH) into another range by more than a |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
224 | hysteresis value. Hysteresis is used to prevent multiple interrupts close to a |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
225 | threshold. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
226 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
227 | The interrupt is disabled by default and can be enabled with function |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
228 | `ccs811_set_eco2_thresholds()`. The ranges are defined by parameters *low* and |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
229 | *high* as following |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
230 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
231 | - **LOW** - below parameter value *low* |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
232 | - **MEDIUM** - between parameter values *low* and *high* |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
233 | - **HIGH** - above parameter value *high* is range **HIGH**. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
234 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
235 | If all parameters have valid values, the function sets the thresholds and |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
236 | enables the data ready interrupt. Using 0 for all parameters disables the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
237 | interrupt. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
238 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
239 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
240 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
241 | // set threshold parameters and enable threshold interrupt mode |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
242 | ESP_ERROR_CHECK(ccs811_set_eco2_thresholds(&sensor, 600, 1100, 40)); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
243 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
244 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
245 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
246 | ### Baseline |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
247 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
248 | CCS81 supports automatic baseline correction over a minimum time of 24 hours. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
249 | Using function `ccs811_get_baseline()`, the current baseline value can be saved |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
250 | before the sensor is powered down. This baseline can then be restored with |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
251 | function `ccs811_set_baseline()` after sensor is powered up again to continue |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
252 | the automatic baseline process. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
253 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
254 | ## Usage |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
255 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
256 | First, the hardware configuration has to be established. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
257 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
258 | ### Communication interface settings |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
259 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
260 | Dependent on the hardware configuration, the communication interface settings |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
261 | have to be defined. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
262 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
263 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
264 | // define I2C interfaces at which CCS811 sensors can be connected |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
265 | #define I2C_PORT 0 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
266 | #define I2C_SCL_PIN 14 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
267 | #define I2C_SDA_PIN 13 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
268 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
269 | // define GPIO for interrupt |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
270 | #define INT_GPIO 5 |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
271 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
272 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
273 | ### Main program |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
274 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
275 | Before using the CCS811 driver, function `i2cdev_init()` needs to be called. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
276 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
277 | **Please note:** CCS811 uses clock streching that can be longer than the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
278 | default I2C clock stretching. Therefore the clock stretching parameter of I2C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
279 | has to be set to at least `CCS811_I2C_CLOCK_STRETCH`. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
280 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
281 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
282 | static ccs811_dev_t sensor; // pointer to sensor device data structure |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
283 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
284 | memset(&sensor, 0, sizeof(ccs811_dev_t)); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
285 | i2cdev_init(); // Init i2cdev library |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
286 | i2c_set_timeout(I2C_PORT, CCS811_I2C_CLOCK_STRETCH); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
287 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
288 | ccs811_init_desc(&sensor, I2C_PORT, CCS811_I2C_ADDRESS_1, I2C_SDA_PIN, I2C_SCL_PIN); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
289 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
290 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
291 | Once I2C library initialized, function `ccs811_init()` has to be called |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
292 | for each CCS811 sensor to initialize the sensor and to check its availability |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
293 | as well as its error state. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
294 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
295 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
296 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
297 | if (ccs811_init(&sensor) == ESP_OK) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
298 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
299 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
300 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
301 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
302 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
303 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
304 | If initialization of the sensor was successful, the sensor mode has be set to |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
305 | start periodic measurement. The sensor mode can be changed anytime later. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
306 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
307 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
308 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
309 | // start periodic measurement with one measurement per second |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
310 | ccs811_set_mode(&sensor, CCS811_MODE_1S); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
311 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
312 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
313 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
314 | Finally, a user task that uses the sensor has to be created. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
315 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
316 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
317 | xTaskCreate(user_task, "user_task", 256, NULL, 2, 0); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
318 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
319 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
320 | The user task can use different approaches to fetch new data. Either new data |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
321 | are fetched periodically or the interrupt signal *nINT* is used when new data |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
322 | are available or eCO2 value exceeds defined thresholds. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
323 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
324 | If new data are fetched **periodically** the implementation of the user task is |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
325 | quite simply and could look like following. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
326 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
327 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
328 | void user_task(void *pvParameters) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
329 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
330 | uint16_t tvoc; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
331 | uint16_t eco2; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
332 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
333 | TickType_t last_wakeup = xTaskGetTickCount(); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
334 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
335 | while (1) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
336 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
337 | // get the results and do something with them |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
338 | if (ccs811_get_results(&sensor, &tvoc, &eco2, 0, 0) == ESP_OK) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
339 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
340 | // passive waiting until 1 second is over |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
341 | vTaskDelayUntil(&last_wakeup, 1000 / portTICK_PERIOD_MS); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
342 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
343 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
344 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
345 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
346 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
347 | The user task simply fetches new data with the same rate as the measurements |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
348 | are performed. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
349 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
350 | **Please note:** The rate of fetching the measurement results must be not |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
351 | greater than the rate of periodic measurements of the sensor, however, it |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
352 | *should be less* to avoid conflicts caused by the timing tolerance of the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
353 | sensor. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
354 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
355 | A different approach is to use the **interrupt** *nINT*. This interrupt signal |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
356 | is either triggered every time when new data are available (INT_DATA_RDY) or |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
357 | only whenever eCO2 value exceeds defined thresholds (INT_THRESHOLD). In both |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
358 | cases, the user has to implement an interrupt handler that either fetches the |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
359 | data directly or triggers a task, that is waiting to fetch the data. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
360 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
361 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
362 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
363 | TaskHandle_t nINT_task; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
364 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
365 | // Interrupt handler which resumes user_task_interrupt on interrupt |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
366 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
367 | void nINT_handler(uint8_t gpio) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
368 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
369 | xTaskResumeFromISR(nINT_task); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
370 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
371 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
372 | // User task that fetches the sensor values. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
373 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
374 | void user_task_interrupt(void *pvParameters) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
375 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
376 | uint16_t tvoc; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
377 | uint16_t eco2; |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
378 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
379 | while (1) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
380 | { |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
381 | // task suspends itself and waits to be resumed by interrupt handler |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
382 | vTaskSuspend(NULL); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
383 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
384 | // after resume get the results and do something with them |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
385 | if (ccs811_get_results(&sensor, &tvoc, &eco2, 0, 0) == ESP_OK) |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
386 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
387 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
388 | } |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
389 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
390 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
391 | xTaskCreate(user_task_interrupt, "user_task_interrupt", 256, NULL, 2, &nINT_task); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
392 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
393 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
394 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
395 | In this example, a task is defined which suspends itself in each cycle to wait |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
396 | for fetching the data. The task is resumed by the interrupt handler. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
397 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
398 | Finally, the interrupt handler has to be activated for the GPIO which is |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
399 | connected to the interrupt signal. Furthermore, the interrupt has to be enabled |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
400 | in the CCS811 sensor. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
401 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
402 | Function `ccs811_enable_interrupt()` enables the interrupt that is triggered |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
403 | whenever new data are available (INT_DATA_RDY). |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
404 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
405 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
406 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
407 | // activate the interrupt for INT_GPIO and set the interrupt handler |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
408 | gpio_set_interrupt(INT_GPIO, GPIO_INTTYPE_EDGE_NEG, nINT_handler); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
409 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
410 | // enable the data ready interrupt INT_DATA_RDY |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
411 | ccs811_enable_interrupt(&sensor, true); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
412 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
413 | ``` |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
414 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
415 | Function `ccs811_set_eco2_thresholds()` enables the interrupt that is triggered |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
416 | whenever eCO2 value exceeds the thresholds (INT_THRESHOLD) defined by parameters. |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
417 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
418 | ```C |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
419 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
420 | // activate the interrupt for INT_GPIO and set the interrupt handler |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
421 | gpio_set_interrupt(INT_GPIO, GPIO_INTTYPE_EDGE_NEG, nINT_handler); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
422 | |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
423 | // set threshold parameters and enable threshold interrupt mode INT_THRESHOLD |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
424 | ccs811_set_eco2_thresholds(&sensor, 600, 1100, 40); |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
425 | ... |
1c9894662795
Added esp-idf-lib for a lot of sensors. Added the basic design for the BMP280 task.
Michiel Broek <mbroek@mbse.eu>
parents:
diff
changeset
|
426 | ``` |