added parameters validation and cosmetic changes

Author: git-user-cpp

Core/Inc/AHT20.h

@@ -47,7 +47,7 @@ typedef struct {
  * Datasheet: AHT20 Product manuals
  * 5.3 Send command
  */
-aht20_status_t aht20_get_calibration_status(I2C_HandleTypeDef *hi2c, UART_HandleTypeDef *huart, uint8_t *status_word, uint16_t status_word_size);
+aht20_status_t aht20_get_calibration_status(I2C_HandleTypeDef *hi2c, uint8_t *status_word, uint16_t status_word_size);
 
 /*
  * checks the 3rd bit of a received variable

Core/Inc/utils.h

@@ -0,0 +1,27 @@
+/*
+ * aht20_driver_stm32f446ret
+ * driver for aht20 temperature and humidity sensor
+ * Copyright (C) 2025 Andrew Kushyk
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include "main.h"
+#include "AHT20.h"
+
+/*
+ * prints error message via UART
+ */
+void print_error(UART_HandleTypeDef *huart, aht20_status_t status);

Core/Src/AHT20.c

@@ -21,6 +21,8 @@
 #include <stdio.h>
 #include <string.h>
 #include <math.h>
+#include <assert.h>
+#include <stddef.h>
 
 /*
  * device address for AHT20
@@ -83,7 +85,10 @@ static uint8_t calculate_crc(uint8_t *data);
  * Datasheet: AHT20 Product manuals
  * 5.3 Send command
  */
-aht20_status_t aht20_get_calibration_status(I2C_HandleTypeDef *hi2c, UART_HandleTypeDef *huart, uint8_t *status_word, uint16_t status_word_size) {
+aht20_status_t aht20_get_calibration_status(I2C_HandleTypeDef *hi2c, uint8_t *status_word, uint16_t status_word_size) {
+	assert(hi2c != NULL);
+	assert(status_word != NULL);
+
 	if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, &GET_STATUS_CMD, (uint16_t)sizeof(GET_STATUS_CMD), HAL_MAX_DELAY)) {
 		return AHT20_STATUS_NOT_TRANSMITTED;
 	}
@@ -116,6 +121,8 @@ aht20_status_t aht20_check_calibration(uint8_t status_word) {
  * 5.4 Sensor reading process, paragraph 1
  */
 aht20_status_t aht20_calibrate(I2C_HandleTypeDef *hi2c, uint8_t status_word) {
+	assert(hi2c != NULL);
+
 	if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, INIT_CMD, (uint16_t)sizeof(INIT_CMD), HAL_MAX_DELAY)) {
 		return AHT20_STATUS_NOT_TRANSMITTED;
 	}
@@ -130,6 +137,9 @@ aht20_status_t aht20_calibrate(I2C_HandleTypeDef *hi2c, uint8_t status_word) {
  * 5.4 Sensor reading process, paragraph 2
  */
 aht20_status_t aht20_measure(I2C_HandleTypeDef *hi2c, uint8_t *measured_data, uint16_t measured_data_size) {
+	assert(hi2c != NULL);
+	assert(measured_data != NULL);
+
 	if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, MEASURE_CMD, (uint16_t)sizeof(MEASURE_CMD), HAL_MAX_DELAY)) {
 		return AHT20_STATUS_NOT_TRANSMITTED;
 	}
@@ -167,6 +177,11 @@ aht20_status_t aht20_measure(I2C_HandleTypeDef *hi2c, uint8_t *measured_data, ui
  * 6.2 Temperature transformation
  */
 void aht20_calculate_measurments(uint8_t *measured_data, float *humidity, float *temp_c, float *temp_f) {
+	assert(measured_data != NULL);
+	assert(humidity != NULL);
+	assert(temp_c != NULL);
+	assert(temp_f != NULL);
+
 	uint32_t raw_humidity = ((measured_data[1] << 12) | (measured_data[2] << 4) | (measured_data[3] >> 4));
 	uint32_t raw_temperature = (((measured_data[3] & 0x0F) << 16) | (measured_data[4] << 8) | measured_data[5]);
 
@@ -182,6 +197,8 @@ void aht20_calculate_measurments(uint8_t *measured_data, float *humidity, float
  * 5.5 Soft reset
  */
 aht20_status_t aht20_soft_reset(I2C_HandleTypeDef *hi2c) {
+	assert(hi2c != NULL);
+
 	if (HAL_OK != HAL_I2C_Master_Transmit(hi2c, DEVICE_ADDRESS, &SOFT_RESET_CMD, (uint16_t)sizeof(SOFT_RESET_CMD), HAL_MAX_DELAY)) {
 		return AHT20_STATUS_NOT_TRANSMITTED;
 	}
@@ -194,6 +211,8 @@ aht20_status_t aht20_soft_reset(I2C_HandleTypeDef *hi2c) {
  * calculates crc8 for given data
  */
 static uint8_t calculate_crc(uint8_t *data) {
+	assert(data != NULL);
+
     uint8_t crc = 0xFF;
     uint8_t i = 0, j = 0;
 

Core/Src/main.c

@@ -26,6 +26,7 @@
 /* Private includes ----------------------------------------------------------*/
 /* USER CODE BEGIN Includes */
 #include "AHT20.h"
+#include "utils.h"
 #include <stdio.h>
 #include <string.h>
 /* USER CODE END Includes */
@@ -69,31 +70,6 @@ void UART_Send_String(const char* str)
 	HAL_UART_Transmit(&huart2, (uint8_t*)str, strlen(str), HAL_MAX_DELAY);
 }
 
-/* prints error message to UART based on received status */
-void print_error(aht20_status_t status) {
-	char debug_msg[64] = "\0";
-
-	if(status == AHT20_STATUS_NOT_TRANSMITTED) {
-		sprintf(debug_msg, "I2C initialization transmit error: 0x71\r\n");
-		UART_Send_String(debug_msg);
-	} else if (status == AHT20_STATUS_NOT_RECEIVED) {
-		sprintf(debug_msg, "I2C initialization recieve error: status_word\r\n");
-		UART_Send_String(debug_msg);
-	} else if (status == AHT20_STATUS_NOT_CALIBRATED) {
-		sprintf(debug_msg, "I2C device calibration error\r\n");
-		UART_Send_String(debug_msg);
-	} else if (status == AHT20_STATUS_NOT_MEASURED) {
-		sprintf(debug_msg, "I2C device couldn't perform measuring\r\n");
-		UART_Send_String(debug_msg);
-	} else if (status == AHT20_STATUS_OK) {
-		/* doing nothing if ok */
-	}
-	else {
-		sprintf(debug_msg, "Unknown error\r\n");
-		UART_Send_String(debug_msg);
-	}
-}
-
 /* transmits data to UART */
 void transmit_data(float humidity, float temperature_c, float temperature_f) {
 	char data_to_display[60] = "\0";
@@ -144,9 +120,9 @@ int main(void)
 	aht20_status_t status = AHT20_STATUS_OK;
 
 	/* getting info about sensor calibration */
-	status = aht20_get_calibration_status(&hi2c1, &huart2, &status_word, (uint16_t)sizeof(status_word));
+	status = aht20_get_calibration_status(&hi2c1, &status_word, (uint16_t)sizeof(status_word));
 	if (status != AHT20_STATUS_OK) {
-		print_error(status);
+		print_error(&huart2, status);
 		return 1;
 	} else {
 		/* checks if calibration is valid */
@@ -155,7 +131,7 @@ int main(void)
 			/* calibrates if not calibrated*/
 			status = aht20_calibrate(&hi2c1, status_word);
 			if (status != AHT20_STATUS_OK) {
-				print_error(status);
+				print_error(&huart2, status);
 				return 2;
 			}
 		}
@@ -172,7 +148,7 @@ int main(void)
 		/* triggering measuring */
 		status = aht20_measure(&hi2c1, sensor_data.measured_data, (uint16_t)sizeof(sensor_data.measured_data));
 		if (status != AHT20_STATUS_OK) {
-			print_error(status);
+			print_error(&huart2, status);
 			aht20_soft_reset(&hi2c1);
 			continue;
 		}

Core/Src/utils.c

@@ -0,0 +1,43 @@
+/*
+ * aht20_driver_stm32f446ret
+ * driver for aht20 temperature and humidity sensor
+ * Copyright (C) 2025 Andrew Kushyk
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "utils.h"
+#include <stdio.h>
+#include <string.h>
+
+/*
+ * prints error message via UART
+ */
+void print_error(UART_HandleTypeDef *huart, aht20_status_t status) {
+    char debug_msg[64] = "\0";
+    if (status == AHT20_STATUS_NOT_TRANSMITTED) {
+        sprintf(debug_msg, "I2C initialization transmit error: 0x71\r\n");
+    } else if (status == AHT20_STATUS_NOT_RECEIVED) {
+        sprintf(debug_msg, "I2C initialization receive error: status_word\r\n");
+    } else if (status == AHT20_STATUS_NOT_CALIBRATED) {
+        sprintf(debug_msg, "I2C device calibration error\r\n");
+    } else if (status == AHT20_STATUS_NOT_MEASURED) {
+        sprintf(debug_msg, "I2C device couldn't perform measuring\r\n");
+    } else if (status == AHT20_STATUS_OK) {
+        return; // No action needed
+    } else {
+        sprintf(debug_msg, "Unknown error\r\n");
+    }
+    HAL_UART_Transmit(huart, (uint8_t*)debug_msg, strlen(debug_msg), HAL_MAX_DELAY);
+}