Question
problem reading data from SCD30 with NUCLEO-L476RG
I am having issues with reading data from the SCD30 CO2 sensor. every byte of data I get back is 0xDD (or 221). I am still learning so my methods may be questionable. If anyone can help narrow down why this is happen and how to fix it, I would be very grateful. here is my code.
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2024 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c3;
UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
static const uint16_t SCD30_ADDR = 0x61 << 1; // Use 8-bit address
static const uint16_t CMD_READ_MEASUREMENT = 0x0300;
static const uint16_t CMD_GET_DATA_READY_STATUS = 0x0202;
static const uint16_t CMD_START_CONTINUOUS_MEASUREMENT = 0x0010;
static const uint16_t CMD_SET_MEASUREMENT_INTERVAL = 0x4600;
static const uint16_t CMD_STOP_CONTINUOUS_MEASUREMENT = 0x0104;
uint8_t Buffer[25] = {0};
uint8_t measurementData[18] = {0};
uint8_t newLine[] = "\r\n";
uint8_t tempMSG[] = "Temperature: ";
uint8_t humiMSG[] = "Humidity: ";
uint8_t buf[12] = {0};
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_I2C3_Init(void);
/* USER CODE BEGIN PFP */
void convertUint16_tToUint8_tArray(uint16_t inputData, uint8_t *storageLocation);
void clearArray(uint8_t *storageLocation);
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
int16_t val;
float temp_c;
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART2_UART_Init();
MX_I2C3_Init();
/* USER CODE BEGIN 2 */
//start continuous measurement mode.
//@todo: crc function for write commands
convertUint16_tToUint8_tArray(CMD_START_CONTINUOUS_MEASUREMENT, buf);
while(HAL_OK != HAL_I2C_Master_Transmit(&hi2c3, SCD30_ADDR, buf, sizeof(buf), HAL_MAX_DELAY));
memset(buf,0,sizeof(buf));
//while(HAL_OK != HAL_I2C_Master_Transmit(&hi2c3, SCD30_ADDR, buf, sizeof(buf), HAL_MAX_DELAY));
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
//condition the data to be sent to the device. the function also clears the array, so no need to use memset()
convertUint16_tToUint8_tArray(CMD_GET_DATA_READY_STATUS, buf);
// Tell SCD30 that we want to read from the temperature register
if(HAL_OK == HAL_I2C_Master_Transmit(&hi2c3, SCD30_ADDR, buf, sizeof(buf), HAL_MAX_DELAY))
{
//clear buffer
memset(buf,0,sizeof(buf));
//get data. in this case, whether or not the sensor is ready to send data
HAL_I2C_Master_Receive(&hi2c3, SCD30_ADDR, buf, sizeof(buf), HAL_MAX_DELAY);
//sensor returns a '1' on the second byte if it is ready
if(buf[1])
{
convertUint16_tToUint8_tArray(CMD_READ_MEASUREMENT, buf);
if(HAL_OK == HAL_I2C_Master_Transmit(&hi2c3, SCD30_ADDR, buf, sizeof(buf), HAL_MAX_DELAY))
{
HAL_I2C_Master_Receive(&hi2c3, SCD30_ADDR, measurementData, sizeof(measurementData), HAL_MAX_DELAY);
}
}
}
HAL_UART_Transmit(&huart2, measurementData, sizeof(measurementData), 10000);
HAL_UART_Transmit(&huart2, newLine, sizeof(newLine), 10000);
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
{
Error_Handler();
}
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 1;
RCC_OscInitStruct.PLL.PLLN = 10;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief I2C3 Initialization Function
* @PAram None
* @retval None
*/
static void MX_I2C3_Init(void)
{
/* USER CODE BEGIN I2C3_Init 0 */
/* USER CODE END I2C3_Init 0 */
/* USER CODE BEGIN I2C3_Init 1 */
/* USER CODE END I2C3_Init 1 */
hi2c3.Instance = I2C3;
hi2c3.Init.Timing = 0x30408CFF;
hi2c3.Init.OwnAddress1 = 0;
hi2c3.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c3.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c3.Init.OwnAddress2 = 0;
hi2c3.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
hi2c3.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c3.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c3) != HAL_OK)
{
Error_Handler();
}
/** Configure Analogue filter
*/
if (HAL_I2CEx_ConfigAnalogFilter(&hi2c3, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
{
Error_Handler();
}
/** Configure Digital filter
*/
if (HAL_I2CEx_ConfigDigitalFilter(&hi2c3, 0) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2C3_Init 2 */
/* USER CODE END I2C3_Init 2 */
}
/**
* @brief USART2 Initialization Function
* @PAram None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 115200;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @PAram None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin : B1_Pin */
GPIO_InitStruct.Pin = B1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : LD2_Pin */
GPIO_InitStruct.Pin = LD2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(LD2_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
/*convert uint16 into a uint8 array. bytes are stored in the order of MSB to LSB.
* ex: uint16_t input = 0x1234;
* uint8_t output[25] = {0x4,0x3,0x2,0x1,0x0,...,0x0}
*/
void convertUint16_tToUint8_tArray(uint16_t inputData, uint8_t *storageLocation)
{
int i = 0,
j = 0;
uint8_t temp;
clearArray(storageLocation);
//write data into the array
for(i = 0; i < sizeof(inputData)*2; i++)
storageLocation[i] = (inputData >> (4*i)) % (sizeof(inputData)*8);
//reverse the data in the array. comment out depending on the endianness of the application.
for(i = 0, j = (sizeof(inputData)*2)-1; i < j ;i++, j-- )
{
temp = storageLocation[i];
storageLocation[i] = storageLocation[j];
storageLocation[j] = temp;
}
}
void clearArray(uint8_t *storageLocation)
{
int i = 0;
for(i = 0; i < sizeof(storageLocation)*8; i++) storageLocation[i] = 0;
}
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @PAram file: pointer to the source file name
* @PAram line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */