main/task_ds18b20.c

/**
 * @file task_ds18b20.c
 * @brief The FreeRTOS task to query the DS18B20 sensors on one or two
 *        one-wire busses. Each bus must have only one sensor. That way
 *        we don't need to care about the DS18B20 internal ROM address.
 *        The task will update the DS18B20_State structure.
 */


#include "owb.h"
#include "owb_rmt.h"
#include "ds18b20.h"
#include "config.h"


#ifdef CONFIG_TEMP_SENSORS_ONEWIRE
#define GPIO_DS18B20_MLT     (CONFIG_ONE_WIRE_MLT)
#define GPIO_DS18B20_HLT     (CONFIG_ONE_WIRE_HLT)
#define MAX_DEVICES          (8)
#define DS18B20_RESOLUTION   (DS18B20_RESOLUTION_12_BIT)
#define SAMPLE_PERIOD        (2000)   // milliseconds
#endif

#ifdef CONFIG_TEMP_SENSORS_SIMULATOR
#define SAMPLE_PERIOD        (750)    // milliseconds

float               	Fake_MLT = 18.90;
float			Fake_HLT = 18.70;
#endif

static const char	*TAG = "task_ds18b20";

SemaphoreHandle_t	xSemaphoreDS18B20 = NULL;
DS18B20_State		*ds18b20_state;


/*
 * Task to read temperature sensors.
 */
void task_ds18b20(void *pvParameter)
{
#ifdef CONFIG_TEMP_SENSORS_ONEWIRE
    int			num_devices = 0;
    float		readings = 0;
    bool		found = false;
    DS18B20_ERROR	errors = 0;
    TickType_t		last_wake_time = xTaskGetTickCount();

    ESP_LOGI(TAG, "Starting DS18B20 sensors");
    ds18b20_state = malloc(sizeof(DS18B20_State));
    ds18b20_state->mlt_valid = ds18b20_state->hlt_valid = false;
    ds18b20_state->mlt_temperature = ds18b20_state->hlt_temperature = 0.0;
    ds18b20_state->mlt_error = ds18b20_state->hlt_error = DS18B20_ERR_NOSENSOR;

    /*
     * Initialize the MLT and HLT one-wire busses.
     */
    OneWireBus *owb_mlt;
    OneWireBus *owb_hlt;
    owb_rmt_driver_info rmt_driver_info_mlt;
    owb_rmt_driver_info rmt_driver_info_hlt;
    owb_mlt = owb_rmt_initialize(&rmt_driver_info_mlt, GPIO_DS18B20_MLT, RMT_CHANNEL_1, RMT_CHANNEL_0);
    owb_hlt = owb_rmt_initialize(&rmt_driver_info_hlt, GPIO_DS18B20_HLT, RMT_CHANNEL_3, RMT_CHANNEL_2);
    owb_use_crc(owb_mlt, true);                     // enable CRC check for ROM code
    owb_use_crc(owb_hlt, true); 

    DS18B20_Info * ds18b20_info = ds18b20_malloc();

    /*
     * Task loop forever.
     */
    while (1) {

	last_wake_time = xTaskGetTickCount();

	num_devices = 0;
	OneWireBus_SearchState mlt_search_state = {0};
	found = false;
	owb_search_first(owb_mlt, &mlt_search_state, &found);
	while (found) {
	    ++num_devices;
	    owb_search_next(owb_mlt, &mlt_search_state, &found);
	}

	if (num_devices == 1) {
	    ds18b20_init_solo(ds18b20_info, owb_mlt);			// only one device on bus
	    ds18b20_use_crc(ds18b20_info, true);			// enable CRC check for temperature readings
	    ds18b20_set_resolution(ds18b20_info, DS18B20_RESOLUTION);	// returns true if ok.

	    // Read temperatures more efficiently by starting conversions on all devices at the same time
	    ds18b20_convert_all(owb_mlt);
	    ds18b20_wait_for_conversion(ds18b20_info);

	    errors = ds18b20_read_temp(ds18b20_info, &readings);

	    if (xSemaphoreTake(xSemaphoreDS18B20, 25) == pdTRUE) {
	    	if (errors == DS18B20_OK) {
		    ds18b20_state->mlt_error = DS18B20_ERR_NONE;
		    ds18b20_state->mlt_valid = true;
		    ds18b20_state->mlt_temperature = readings;
	    	} else {
		    if (errors == DS18B20_ERROR_CRC)
		    	ds18b20_state->mlt_error = DS18B20_ERR_CRC;
		    if (errors == DS18B20_ERROR_OWB)
		    	ds18b20_state->mlt_error = DS18B20_ERR_READ;
		    if (errors == DS18B20_ERROR_DEVICE)
		    	ds18b20_state->mlt_error = DS18B20_ERR_READ;
		    ds18b20_state->mlt_valid = false;
		    ds18b20_state->mlt_temperature = 0.0;
	    	}
		xSemaphoreGive(xSemaphoreDS18B20);
	    }

	} else {
	    /*
	     * Zero or more then one device, this is an error.
	     */
	    if (xSemaphoreTake(xSemaphoreDS18B20, 25) == pdTRUE) {
	    	if (num_devices == 0)
		    ds18b20_state->mlt_error = DS18B20_ERR_NOSENSOR;
	    	else
		    ds18b20_state->mlt_error = DS18B20_ERR_TOOMANY;
	    	ds18b20_state->mlt_valid = false;
	    	ds18b20_state->mlt_temperature = 0.0;
		xSemaphoreGive(xSemaphoreDS18B20);
	    }
	} // if num_devices == 1

	num_devices = 0;
	OneWireBus_SearchState hlt_search_state = {0};
	found = false;
	owb_search_first(owb_hlt, &hlt_search_state, &found);
	while (found) {
	    ++num_devices;
	    owb_search_next(owb_hlt, &hlt_search_state, &found);
	}

	if (num_devices == 1) {
	    ds18b20_init_solo(ds18b20_info, owb_hlt);                   // only one device on bus
	    ds18b20_use_crc(ds18b20_info, true);                        // enable CRC check for temperature readings
	    ds18b20_set_resolution(ds18b20_info, DS18B20_RESOLUTION);

	    // Read temperatures more efficiently by starting conversions on all devices at the same time
	    ds18b20_convert_all(owb_hlt);
	    ds18b20_wait_for_conversion(ds18b20_info);
	
	    errors = ds18b20_read_temp(ds18b20_info, &readings);
	
	    if (xSemaphoreTake(xSemaphoreDS18B20, 25) == pdTRUE) {
	    	if (errors == DS18B20_OK) {
		    ds18b20_state->hlt_error = DS18B20_ERR_NONE;
		    ds18b20_state->hlt_valid = true;
		    ds18b20_state->hlt_temperature = readings;
	    	} else {
		    if (errors == DS18B20_ERROR_CRC)
		    	ds18b20_state->hlt_error = DS18B20_ERR_CRC;
		    if (errors == DS18B20_ERROR_OWB)
		    	ds18b20_state->hlt_error = DS18B20_ERR_READ;
		    if (errors == DS18B20_ERROR_DEVICE)
		    	ds18b20_state->hlt_error = DS18B20_ERR_READ;
		    ds18b20_state->hlt_valid = false;
		    ds18b20_state->hlt_temperature = 0.0;
	    	}
		xSemaphoreGive(xSemaphoreDS18B20);
	    }
	} else {
	    /*
	     * Zero or more then one device, this is an error.
	     */
	    if (xSemaphoreTake(xSemaphoreDS18B20, 25) == pdTRUE) {
	    	if (num_devices == 0)
		    ds18b20_state->hlt_error = DS18B20_ERR_NOSENSOR;
	    	else
		    ds18b20_state->hlt_error = DS18B20_ERR_TOOMANY;
	    	ds18b20_state->hlt_valid = false;
	    	ds18b20_state->hlt_temperature = 0.0;
		xSemaphoreGive(xSemaphoreDS18B20);
	    }
	} // if num_devices == 1

#if 0
	printf("MLT  %.3f  %d err %s, HLT  %.3f,  %d err %s\n",
		ds18b20_state->mlt_temperature, ds18b20_state->mlt_error, (ds18b20_state->mlt_valid) ? "valid":" N/A ",
		ds18b20_state->hlt_temperature, ds18b20_state->hlt_error, (ds18b20_state->hlt_valid) ? "valid":" N/A ");
#endif
	vTaskDelayUntil(&last_wake_time, SAMPLE_PERIOD / portTICK_PERIOD_MS);
    }
#endif

#ifdef CONFIG_TEMP_SENSORS_SIMULATOR

    float		Plate_MLT = 18.90;
    extern int		MLT_pin, HLT_pin;

    ESP_LOGI(TAG, "Starting Fake sensors");
    ds18b20_state = malloc(sizeof(DS18B20_State));
    ds18b20_state->mlt_valid = ds18b20_state->hlt_valid = true;
    ds18b20_state->mlt_temperature = 18.90;
    ds18b20_state->hlt_temperature = 18.70;
    ds18b20_state->mlt_error = ds18b20_state->hlt_error = DS18B20_ERR_NONE;

    /*
     * Task loop forever. Update the temperatures each 750 mSeconds.
     */
    while (1) {

	/*
	 * Make this fake heater a bit more real by using a simulated heatplate.
	 * We heatup that plate and then transfer the heat to the water.
	 * That way we get a nice overshoot like in real life.
	 */
	if (MLT_pin) {
	    if (Plate_MLT < 250.0)
		Plate_MLT += SAMPLE_PERIOD * 0.001;   // Simulate plate upto 250 degrees
	} else {
	    if (Plate_MLT > Fake_MLT)
		Plate_MLT -= SAMPLE_PERIOD * 0.00002 * (Plate_MLT - Fake_MLT);
	}
	// If plate is hotter then the water with a offset so that cooling later works.
	if (Plate_MLT > (Fake_MLT + 5.0)) {
	    if (Fake_MLT < 100.05)
		Fake_MLT += SAMPLE_PERIOD * 0.000001 * (Plate_MLT - Fake_MLT);
	}
	// Allways loose heat to the air
	if (Fake_MLT > 16.0) {
	    Fake_MLT -= SAMPLE_PERIOD * 0.00000010 * (Fake_MLT - 16.0);
	}

	if ((equipment.SSR2 == SSR2_HLT_SHARE) || (equipment.SSR2 == SSR2_HLT_IND)) {
	    /*
	     * There is a HLT function configured.
	     */
	    if (HLT_pin) {
	    	if (Fake_HLT < 100.05)
		    Fake_HLT += SAMPLE_PERIOD * 0.000055;
	    } else {
	    	if (Fake_HLT > 16.0)
		    Fake_HLT -= SAMPLE_PERIOD * 0.00000006 * (Fake_HLT - 16.0);
	    }
	}

	if (xSemaphoreTake(xSemaphoreDS18B20, 25) == pdTRUE) {
	    ds18b20_state->mlt_temperature = ((int)(Fake_MLT * 16)) / 16.0;
	    ds18b20_state->hlt_temperature = ((int)(Fake_HLT * 16)) / 16.0;
	    xSemaphoreGive(xSemaphoreDS18B20);
	}

	vTaskDelay(SAMPLE_PERIOD / portTICK_PERIOD_MS);
    }

#endif
}