esp-idf/examples/peripherals/rmt/onewire_ds18b20/main/ds18b20.h

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2022-07-04 06:42:19 -04:00
/*
* SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
#pragma once
#include "onewire_bus.h"
#define DS18B20_CMD_CONVERT_TEMP 0x44
#define DS18B20_CMD_WRITE_SCRATCHPAD 0x4E
#define DS18B20_CMD_READ_SCRATCHPAD 0xBE
/**
* @brief Structure of DS18B20's scratchpad
*
*/
typedef struct {
uint8_t temp_lsb; /*!< lsb of temperature */
uint8_t temp_msb; /*!< msb of temperature */
uint8_t th_user1; /*!< th register or user byte 1 */
uint8_t tl_user2; /*!< tl register or user byte 2 */
uint8_t configuration; /*!< configuration register */
uint8_t _reserved1;
uint8_t _reserved2;
uint8_t _reserved3;
uint8_t crc_value; /*!< crc value of scratchpad data */
} ds18b20_scratchpad_t;
/**
* @brief Enumeration of DS18B20's resolution config
*
*/
typedef enum {
DS18B20_RESOLUTION_12B = 0x7F, /*!< 750ms convert time */
DS18B20_RESOLUTION_11B = 0x5F, /*!< 375ms convert time */
DS18B20_RESOLUTION_10B = 0x3F, /*!< 187.5ms convert time */
DS18B20_RESOLUTION_9B = 0x1F, /*!< 93.75ms convert time */
} ds18b20_resolution_t;
/**
* @brief Trigger temperature conversion of DS18B20
*
* @param[in] handle 1-wire handle with DS18B20 on
* @param[in] rom_number ROM number to specify which DS18B20 to send command, NULL to skip ROM
* @return
* - ESP_OK Trigger tempreture convertsion success.
* - ESP_ERR_INVALID_ARG Invalid argument.
* - ESP_ERR_NOT_FOUND There is no device present on 1-wire bus.
*/
esp_err_t ds18b20_trigger_temperature_conversion(onewire_bus_handle_t handle, const uint8_t *rom_number);
/**
* @brief Get temperature from DS18B20
*
* @param[in] handle 1-wire handle with DS18B20 on
* @param[in] rom_number ROM number to specify which DS18B20 to read from, NULL to skip ROM
* @param[out] temperature result from DS18B20
* @return
* - ESP_OK Get tempreture from DS18B20 success.
* - ESP_ERR_INVALID_ARG Invalid argument.
* - ESP_ERR_NOT_FOUND There is no device present on 1-wire bus.
* - ESP_ERR_INVALID_CRC CRC check failed.
*/
esp_err_t ds18b20_get_temperature(onewire_bus_handle_t handle, const uint8_t *rom_number, float *temperature);
/**
* @brief Set DS18B20's temperation conversion resolution
*
* @param[in] handle 1-wire handle with DS18B20 on
* @param[in] rom_number ROM number to specify which DS18B20 to read from, NULL to skip ROM
* @param[in] resolution resolution of DS18B20's temperation conversion
* @return
* - ESP_OK Set DS18B20 resolution success.
* - ESP_ERR_INVALID_ARG Invalid argument.
* - ESP_ERR_NOT_FOUND There is no device present on 1-wire bus.
*/
esp_err_t ds18b20_set_resolution(onewire_bus_handle_t handle, const uint8_t *rom_number, ds18b20_resolution_t resolution);