trying to get data from MAX144 external ADC using STM32L452RE micro controller but no success :(

Question

I m quite new with using ADC. I am using an external ADC MAX144 to get sensor data using STM32L452RE. I am using both channels of this ADC for two sensors. ADC is continuously sending data and I want to read it.

datasheet of ADC is here

what I am doing is:

1. created a 2 byte buffer
2. i am using DMA for both spi and uart
3. receiving data in buffer with HAL_SPI_Receive_DMA()
4. transmitting data over usart using HAL_UART_Transmit_DMA()

code that i have made is given below:

#include "main.h"
#include "stm32l4xx_hal.h"

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private variables ---------------------------------------------------------*/
SPI_HandleTypeDef hspi3;
DMA_HandleTypeDef hdma_spi3_rx;

TIM_HandleTypeDef htim1;

UART_HandleTypeDef huart3;
DMA_HandleTypeDef hdma_usart3_tx;

/* USER CODE BEGIN PV */
/* Private variables --------------------------------------------------- 
 ------*/

static uint8_t readBuffer[2];
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
 void SystemClock_Config(void);
 static void MX_GPIO_Init(void);
 static void MX_DMA_Init(void);
 static void MX_USART3_UART_Init(void);
 static void MX_SPI3_Init(void);
 static void MX_TIM1_Init(void);

 /* USER CODE BEGIN PFP */
 /* Private function prototypes -----------------------------------------------*/

 /* USER CODE END PFP */

/* USER CODE BEGIN 0 */

void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *hspi){
while(1);
}

void UART_DMATransmitCplt(DMA_HandleTypeDef *hdma){
while(1);
}
`enter code here`void delay(uint16_t delay)
 {
__HAL_TIM_SET_COUNTER(&htim1,0);
while(__HAL_TIM_GET_COUNTER(&htim1) < delay);
 }

 /* USER CODE END 0 */

  /**
  * @brief  The application entry point.
  *
  * @retval None
  */
 int main(void)
 {
 /* USER CODE BEGIN 1 */

/* 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_DMA_Init();
MX_USART3_UART_Init();
MX_SPI3_Init();
MX_TIM1_Init();
/* USER CODE BEGIN 2 */

/* USER CODE END 2 */

/* Infinite loop */
/* USER CODE BEGIN WHILE */
 while (1)
{

 /* USER CODE END WHILE */

/* USER CODE BEGIN 3 */

  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, SET);

  HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_13);
  HAL_Delay(80);

  HAL_SPI_Receive_DMA(&hspi3, readBuffer, 2);
  HAL_UART_Transmit_DMA(&huart3, readBuffer, 2);
}
/* USER CODE END 3 */

}

I am stuck in this problem for the last two weeks. any guides in this regards will be highly appreciated.

regards.

Answer 1

These Callbacks doesn't work

void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *hspi){
    while(1);
}

void UART_DMATransmitCplt(DMA_HandleTypeDef *hdma){
    while(1);
}

The Callbacks are called directly from the Interrupt routines. If you put a while(1) in there the interrupt will never finish.

Make a first try without the DMA functions.

HAL_SPI_Receive(&hspi3, readBuffer, 2);
HAL_UART_Transmit(&huart3, readBuffer, 2);

And see if your SPI ready ind USART writing works. As a second step you could try to setup the DMA transfer.