data was packed into structure, measuring fun was improved

Author: git-user-cpp

Core/Inc/AHT20.h

@@ -31,6 +31,12 @@ typedef enum {
 	AHT20_STATUS_NOT_MEASURED,
 } aht20_status_t;
 
+typedef struct {
+	uint8_t measured_data[7];
+	float humidity;
+	float temperature_c;
+	float temperature_f;
+} aht20_data_t;
 /*
  * sends reads status_word for further calibration verification
  *

Core/Src/AHT20.c

@@ -62,6 +62,16 @@ static uint8_t INIT_CMD[3] = {0xbe, 0x08, 0x00};
  */
 static uint8_t MEASURE_CMD[3] = {0xac, 0x33, 0x00};
 
+/*
+ * acknowledge signal
+ */
+static uint8_t ACK_CMD = 0x06;
+
+/*
+ * not acknowledge signal
+ */
+static uint8_t NACK_CMD = 0x15;
+
 /*
  * calculates crc8 for given data
  */
@@ -133,15 +143,13 @@ aht20_status_t aht20_measure(I2C_HandleTypeDef *hi2c, uint8_t *measured_data, ui
 		return AHT20_STATUS_NOT_MEASURED;
 	}
 
-	uint8_t calculated_crc = calculate_crc(measured_data + 1);
-	if (calculated_crc == measured_data[0]) {
-		uint8_t ack = 0x06;
-		if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, &ack, (uint16_t)sizeof(ack), HAL_MAX_DELAY)) {
+	uint8_t calculated_crc = calculate_crc(measured_data);
+	if (calculated_crc == measured_data[6]) {
+		if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, &ACK_CMD, (uint16_t)sizeof(ACK_CMD), HAL_MAX_DELAY)) {
 			return AHT20_STATUS_NOT_TRANSMITTED;
 		}
 	} else {
-		uint8_t nack = 0x15;
-		if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, &nack, (uint16_t)sizeof(nack), HAL_MAX_DELAY)) {
+		if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, &NACK_CMD, (uint16_t)sizeof(NACK_CMD), HAL_MAX_DELAY)) {
 			return AHT20_STATUS_NOT_TRANSMITTED;
 		}
 

Core/Src/main.c

@@ -145,7 +145,6 @@ int main(void)
 
 	/* getting info about sensor calibration */
 	status = aht20_get_calibration_status(&hi2c1, &huart2, &status_word, (uint16_t)sizeof(status_word));
-
 	if (status != AHT20_STATUS_OK) {
 		print_error(status);
 		return 1;
@@ -155,7 +154,6 @@ int main(void)
 		if (status != AHT20_STATUS_OK) {
 			/* calibrates if not calibrated*/
 			status = aht20_calibrate(&hi2c1, status_word);
-
 			if (status != AHT20_STATUS_OK) {
 				print_error(status);
 				return 2;
@@ -167,23 +165,20 @@ int main(void)
 
 	/* Infinite loop */
 	/* USER CODE BEGIN WHILE */
-	uint8_t measured_data[7] = {0};
-	float humidity = 0.0;
-	float temperature_c = 0.0;
-	float temperature_f = 0.0;
+	aht20_data_t sensor_data = {0};
 
 	while (1)
 	{
 		/* triggering measuring */
-		status = aht20_measure(&hi2c1, measured_data, (uint16_t)sizeof(measured_data));
+		status = aht20_measure(&hi2c1, sensor_data.measured_data, (uint16_t)sizeof(sensor_data.measured_data));
 		if (status != AHT20_STATUS_OK) {
 			print_error(status);
 			aht20_soft_reset(&hi2c1);
 			continue;
 		}
 
-		aht20_calculate_measurments(measured_data, &humidity, &temperature_c, &temperature_f);
-		transmit_data(humidity, temperature_c, temperature_f);
+		aht20_calculate_measurments(sensor_data.measured_data, &sensor_data.humidity, &sensor_data.temperature_c, &sensor_data.temperature_f);
+		transmit_data(sensor_data.humidity, sensor_data.temperature_c, sensor_data.temperature_f);
 
 		HAL_Delay(1000);
 		/* USER CODE END WHILE */