197 lines
7.8 KiB
C
197 lines
7.8 KiB
C
/*
|
|
* 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 "../esp32-owb/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.
|
|
* @param[in] rom_code Device-specific ROM code to identify a device on the bus.
|
|
*/
|
|
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.
|
|
*/
|
|
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] bus Pointer to initialised bus instance.
|
|
* @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
|