diff -r 000000000000 -r 88d965579617 components/esp32-ds18b20/include/ds18b20.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/components/esp32-ds18b20/include/ds18b20.h Tue Oct 08 12:00:31 2019 +0200 @@ -0,0 +1,196 @@ +/* + * MIT License + * + * Copyright (c) 2017 David Antliff + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +/** + * @file ds18b20.h + * @brief Interface definitions for the Maxim Integrated DS18B20 Programmable + * Resolution 1-Wire Digital Thermometer device. + * + * This component provides structures and functions that are useful for communicating + * with DS18B20 devices connected via a Maxim Integrated 1-Wire® bus. + */ + +#ifndef DS18B20_H +#define DS18B20_H + +#include "owb.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief Success and error codes. + */ +typedef enum +{ + DS18B20_ERROR_UNKNOWN = -1, + DS18B20_OK = 0, + DS18B20_ERROR_DEVICE, ///< A device error occurred + DS18B20_ERROR_CRC, ///< A CRC error occurred + DS18B20_ERROR_OWB, ///< A One Wire Bus error occurred + DS18B20_ERROR_NULL, ///< A parameter or value is NULL +} DS18B20_ERROR; + +/** + * @brief Symbols for the supported temperature resolution of the device. + */ +typedef enum +{ + DS18B20_RESOLUTION_INVALID = -1, ///< Invalid resolution + DS18B20_RESOLUTION_9_BIT = 9, ///< 9-bit resolution, LSB bits 2,1,0 undefined + DS18B20_RESOLUTION_10_BIT = 10, ///< 10-bit resolution, LSB bits 1,0 undefined + DS18B20_RESOLUTION_11_BIT = 11, ///< 11-bit resolution, LSB bit 0 undefined + DS18B20_RESOLUTION_12_BIT = 12, ///< 12-bit resolution (default) +} DS18B20_RESOLUTION; + +/** + * @brief Structure containing information related to a single DS18B20 device connected + * via a 1-Wire bus. + */ +typedef struct +{ + bool init; ///< True if struct has been initialised, otherwise false + bool solo; ///< True if device is intended to be the only one connected to the bus, otherwise false + bool use_crc; ///< True if CRC checks are to be used when retrieving information from a device on the bus + const OneWireBus * bus; ///< Pointer to 1-Wire bus information relevant to this device + OneWireBus_ROMCode rom_code; ///< The ROM code used to address this device on the bus + DS18B20_RESOLUTION resolution; ///< Temperature measurement resolution per reading +} DS18B20_Info; + +/** + * @brief Construct a new device info instance. + * New instance should be initialised before calling other functions. + * @return Pointer to new device info instance, or NULL if it cannot be created. + */ +DS18B20_Info * ds18b20_malloc(void); + +/** + * @brief Delete an existing device info instance. + * @param[in] ds18b20_info Pointer to device info instance. + * @param[in,out] ds18b20_info Pointer to device info instance that will be freed and set to NULL. + */ +void ds18b20_free(DS18B20_Info ** ds18b20_info); + +/** + * @brief Initialise a device info instance with the specified GPIO. + * @param[in] ds18b20_info Pointer to device info instance. + * @param[in] bus Pointer to initialised 1-Wire bus instance. + * @param[in] rom_code Device-specific ROM code to identify a device on the bus. + */ +void ds18b20_init(DS18B20_Info * ds18b20_info, const OneWireBus * bus, OneWireBus_ROMCode rom_code); + +/** + * @brief Initialise a device info instance with the specified GPIO as a solo device on the bus. + * + * This is subject to the requirement that this device is the ONLY device on the bus. + * This allows for faster commands to be used without ROM code addressing. + * + * NOTE: if additional devices are added to the bus, operation will cease to work correctly. + * + * @param[in] ds18b20_info Pointer to device info instance. + * @param[in] bus Pointer to initialised 1-Wire bus instance. + */ +void ds18b20_init_solo(DS18B20_Info * ds18b20_info, const OneWireBus * bus); + +/** + * @brief Enable or disable use of CRC checks on device communications. + * @param[in] ds18b20_info Pointer to device info instance. + * @param[in] use_crc True to enable CRC checks, false to disable. + */ +void ds18b20_use_crc(DS18B20_Info * ds18b20_info, bool use_crc); + +/** + * @brief Set temperature measurement resolution. + * + * This programs the hardware to the specified resolution and sets the cached value to be the same. + * If the program fails, the value currently in hardware is used to refresh the cache. + * + * @param[in] ds18b20_info Pointer to device info instance. + * @param[in] resolution Selected resolution. + * @return True if successful, otherwise false. + */ +bool ds18b20_set_resolution(DS18B20_Info * ds18b20_info, DS18B20_RESOLUTION resolution); + +/** + * @brief Update and return the current temperature measurement resolution from the device. + * @param[in] ds18b20_info Pointer to device info instance. + * @return The currently configured temperature measurement resolution. + */ +DS18B20_RESOLUTION ds18b20_read_resolution(DS18B20_Info * ds18b20_info); + +/** + * @brief Read 64-bit ROM code from device - only works when there is a single device on the bus. + * @param[in] ds18b20_info Pointer to device info instance. + * @return The 64-bit value read from the device's ROM. + */ +OneWireBus_ROMCode ds18b20_read_rom(DS18B20_Info * ds18b20_info); + +/** + * @brief Start a temperature measurement conversion on a single device. + * @param[in] ds18b20_info Pointer to device info instance. + * @return True if successfull. + */ +bool ds18b20_convert(const DS18B20_Info * ds18b20_info); + +/** + * @brief Start temperature conversion on all connected devices. + * + * This should be followed by a sufficient delay to ensure all devices complete + * their conversion before the measurements are read. + * @param[in] bus Pointer to initialised bus instance. + */ +void ds18b20_convert_all(const OneWireBus * bus); + +/** + * @brief Wait for the maximum conversion time according to the current resolution of the device. + * @param[in] ds18b20_info Pointer to device info instance. Must be initialised first. + * @return An estimate of the time elapsed, in milliseconds. Actual elapsed time may be greater. + */ +float ds18b20_wait_for_conversion(const DS18B20_Info * ds18b20_info); + +/** + * @brief Read last temperature measurement from device. + * + * This is typically called after ds18b20_start_mass_conversion(), provided enough time + * has elapsed to ensure that all devices have completed their conversions. + * @param[in] ds18b20_info Pointer to device info instance. Must be initialised first. + * @param[out] value Pointer to the measurement value returned by the device, in degrees Celsius. + * @return DS18B20_OK if read is successful, otherwise error. + */ +DS18B20_ERROR ds18b20_read_temp(const DS18B20_Info * ds18b20_info, float * value); + +/** + * @brief Convert, wait and read current temperature from device. + * @param[in] ds18b20_info Pointer to device info instance. Must be initialised first. + * @param[out] value Pointer to the measurement value returned by the device, in degrees Celsius. + * @return DS18B20_OK if read is successful, otherwise error. + */ +DS18B20_ERROR ds18b20_convert_and_read_temp(const DS18B20_Info * ds18b20_info, float * value); + +#ifdef __cplusplus +} +#endif + +#endif // DS18B20_H