#include "zh_aht.h" #define I2C_MAX_DATA_SIZE 7 // Sensor maximum data size (in bytes). #define MEASUREMENT_TIME 80 // Sensor measurement time (in milliseconds). #define RESET_TIME 20 // Sensor reset time (in milliseconds). #define I2C_ADDRESS 0x38 // Sensor I2C address. #define I2C_DATA_READ_COMMAND 0xAC, 0x33, 0x00 // Command for read sensor data (temperature and humidity). #define I2C_RESET_COMMAND 0xBA // Command for reset sensor. #define I2C_INIT_COMMAND 0x00, 0x08, 0x00 // Command for initialize sensor. First byte is depend of sensor type. #define I2C_INIT_AHT1X_FIRST_BYTE 0xE1 // First byte for command for initialize sensor. For AHT1X series. #define I2C_INIT_AHT2X_FIRST_BYTE 0xBE // First byte for command for initialize sensor. For AHT2X/3X series. #define I2C_STATUS_READ_COMMAND 0x71 // Command for read sensor status. static zh_aht_init_config_t _init_config = {0}; static bool _is_initialized = false; #ifndef CONFIG_IDF_TARGET_ESP8266 static i2c_master_dev_handle_t _aht_handle = {0}; #endif static const char *TAG = "zh_aht"; static uint8_t _calc_crc(const uint8_t *buf, size_t len); esp_err_t zh_aht_init(const zh_aht_init_config_t *config) { ESP_LOGI(TAG, "AHT initialization begin."); if (config == NULL) { ESP_LOGE(TAG, "AHT initialization fail. Invalid argument."); return ESP_ERR_INVALID_ARG; } _init_config = *config; #ifndef CONFIG_IDF_TARGET_ESP8266 i2c_device_config_t aht_config = { .dev_addr_length = I2C_ADDR_BIT_LEN_7, .device_address = I2C_ADDRESS, .scl_speed_hz = 100000, }; i2c_master_bus_add_device(_init_config.i2c_handle, &aht_config, &_aht_handle); if (i2c_master_probe(_init_config.i2c_handle, I2C_ADDRESS, 1000 / portTICK_PERIOD_MS) != ESP_OK) { ESP_LOGE(TAG, "AHT initialization fail. Sensor not connected or not responded."); return ESP_ERR_NOT_FOUND; } #endif esp_err_t err = ESP_OK; uint8_t status_read_command = I2C_STATUS_READ_COMMAND; uint8_t sensor_data = 0; #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle_t i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_WRITE, true); i2c_master_write_byte(i2c_cmd_handle, status_read_command, true); i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_transmit(_aht_handle, &status_read_command, sizeof(status_read_command), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { ESP_LOGE(TAG, "AHT initialization fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_READ, true); i2c_master_read_byte(i2c_cmd_handle, &sensor_data, I2C_MASTER_NACK); i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_receive(_aht_handle, &sensor_data, sizeof(sensor_data), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { ESP_LOGE(TAG, "AHT initialization fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } if ((sensor_data & 0x08) == 0) // If sensor is not calibrated. { uint8_t init_command[] = {I2C_INIT_COMMAND}; uint8_t check_command = I2C_INIT_AHT2X_FIRST_BYTE; bool is_first_check = false; INIT_SENSOR:; #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_WRITE, true); i2c_master_write_byte(i2c_cmd_handle, check_command, true); i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_transmit(_aht_handle, &check_command, sizeof(check_command), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { if (err == ESP_ERR_INVALID_STATE && is_first_check == false) { check_command = I2C_INIT_AHT1X_FIRST_BYTE; is_first_check = true; goto INIT_SENSOR; } else { ESP_LOGE(TAG, "AHT initialization fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } } init_command[0] = check_command; #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_WRITE, true); i2c_master_write_byte(i2c_cmd_handle, init_command[0], true); i2c_master_write_byte(i2c_cmd_handle, init_command[1], true); i2c_master_write_byte(i2c_cmd_handle, init_command[2], true); i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_transmit(_aht_handle, init_command, sizeof(init_command), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { ESP_LOGE(TAG, "AHT initialization fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } } ESP_LOGI(TAG, "AHT initialization success."); _is_initialized = true; return ESP_OK; } esp_err_t zh_aht_read(float *humidity, float *temperature) { ESP_LOGI(TAG, "AHT read begin."); if (humidity == NULL || temperature == NULL) { ESP_LOGE(TAG, "AHT read fail. Invalid argument."); return ESP_ERR_INVALID_ARG; } if (_is_initialized == false) { ESP_LOGE(TAG, "AHT read fail. AHT not initialized."); return ESP_ERR_NOT_FOUND; } esp_err_t err = ESP_OK; uint8_t sensor_data[I2C_MAX_DATA_SIZE] = {0}; uint8_t data_read_command[] = {I2C_DATA_READ_COMMAND}; #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle_t i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_WRITE, true); i2c_master_write_byte(i2c_cmd_handle, data_read_command[0], true); i2c_master_write_byte(i2c_cmd_handle, data_read_command[1], true); i2c_master_write_byte(i2c_cmd_handle, data_read_command[2], true); i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_transmit(_aht_handle, data_read_command, sizeof(data_read_command), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { ESP_LOGE(TAG, "AHT read fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } vTaskDelay(MEASUREMENT_TIME / portTICK_PERIOD_MS); #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_READ, true); for (uint8_t i = 0; i < sizeof(sensor_data); ++i) { i2c_master_read_byte(i2c_cmd_handle, &sensor_data[i], i == (sizeof(sensor_data) - 1) ? I2C_MASTER_NACK : I2C_MASTER_ACK); } i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_receive(_aht_handle, sensor_data, sizeof(sensor_data), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { ESP_LOGE(TAG, "AHT read fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } if ((sensor_data[0] & 0x40) != 0) // If sensor is busy in measurement. { ESP_LOGE(TAG, "AHT read fail. Timeout exceeded."); return ESP_ERR_TIMEOUT; } if (sensor_data[6] != 0x00 || sensor_data[6] != 0xFF) { if (_calc_crc(sensor_data, I2C_MAX_DATA_SIZE - 1) != sensor_data[6]) { ESP_LOGE(TAG, "AHT read fail. Invalid CRC."); return ESP_ERR_INVALID_CRC; } } *humidity = (((((uint32_t)sensor_data[1]) << 16) | (((uint32_t)sensor_data[2]) << 8) | (((uint32_t)sensor_data[3]) << 0)) >> 4) / 1048576.0 * 100.0; *temperature = (((((uint32_t)sensor_data[3]) << 16) | (((uint32_t)sensor_data[4]) << 8) | (((uint32_t)sensor_data[5]) << 0)) & 0xFFFFF) / 1048576.0 * 200.0 - 50.0; ESP_LOGI(TAG, "AHT read success."); return ESP_OK; } esp_err_t zh_aht_reset(void) { ESP_LOGI(TAG, "AHT reset begin."); if (_is_initialized == false) { ESP_LOGE(TAG, "AHT reset fail. AHT not initialized."); return ESP_ERR_NOT_FOUND; } esp_err_t err = ESP_OK; uint8_t reset_command = I2C_RESET_COMMAND; #ifdef CONFIG_IDF_TARGET_ESP8266 i2c_cmd_handle_t i2c_cmd_handle = i2c_cmd_link_create(); i2c_master_start(i2c_cmd_handle); i2c_master_write_byte(i2c_cmd_handle, I2C_ADDRESS << 1 | I2C_MASTER_WRITE, true); i2c_master_write_byte(i2c_cmd_handle, reset_command, true); i2c_master_stop(i2c_cmd_handle); err = i2c_master_cmd_begin(_init_config.i2c_port, i2c_cmd_handle, 1000 / portTICK_PERIOD_MS); i2c_cmd_link_delete(i2c_cmd_handle); #else err = i2c_master_transmit(_aht_handle, &reset_command, sizeof(reset_command), 1000 / portTICK_PERIOD_MS); #endif if (err != ESP_OK) { ESP_LOGE(TAG, "AHT reset fail. I2C driver error at line %d.", __LINE__); return ESP_ERR_INVALID_RESPONSE; } vTaskDelay(RESET_TIME / portTICK_PERIOD_MS); ESP_LOGI(TAG, "AHT reset success."); return ESP_OK; } static uint8_t _calc_crc(const uint8_t *buf, size_t len) { uint8_t crc = 0xFF; for (uint8_t byte = 0; byte < len; byte++) { crc ^= buf[byte]; for (uint8_t i = 8; i > 0; --i) { if ((crc & 0x80) != 0) { crc = (crc << 1) ^ 0x31; } else { crc = crc << 1; } } } return crc; }