SPI Slave randomly ignores bytes from SPI master with interrupt mode

[giangthewalkingman]

Hello everyone, nice to meet you all. This is my very first post in this community though I 've been programming on stm32 boards for more than a year, so if I make any mistakes, please let me know so that I can improve later. Thanks very much and hope you all have a nice day!!!

My problem is the SPI communication between the blue pill board STM32F103C8T6 (slave) and the Arduino Uno R3 board (master). Here is my setup:

1. For arduino:

The code:

#include <SPI.h>

#define SS 10

void setup() {

  Serial.begin(9600);

  pinMode(SS, OUTPUT);

  SPI.begin();

}

void dataTransfer(uint8_t data) {

  digitalWrite(SS, LOW);

  SPI.transfer(data);

  digitalWrite(SS, HIGH);

}

void loop() {

  for(int i = 0; i < 10; i++) {

    dataTransfer(i+1);

    Serial.print(i+1);

    Serial.print("\t");

    delay(1000);

  }

  Serial.print("\n");

}

2. For STM32:

Here is my SPI2 configuration:

static void MX_SPI2_Init(void)
{
 hspi2.Instance = SPI2;
 hspi2.Init.Mode = SPI_MODE_SLAVE;
 hspi2.Init.Direction = SPI_DIRECTION_2LINES;
 hspi2.Init.DataSize = SPI_DATASIZE_8BIT;
 hspi2.Init.CLKPolarity = SPI_POLARITY_HIGH;
 hspi2.Init.CLKPhase = SPI_PHASE_2EDGE;
 hspi2.Init.NSS = SPI_NSS_HARD_INPUT;
 hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
 hspi2.Init.TIMode = SPI_TIMODE_DISABLE;
 hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
 hspi2.Init.CRCPolynomial = 10;
if (HAL_SPI_Init(&hspi2) != HAL_OK)
 {
 Error_Handler();
 }
/* USER CODE BEGIN SPI2_Init 2 */
/* USER CODE END SPI2_Init 2 */
}

 my main.c of stm32:

int main(void)
{
 HAL_Init();
 SystemClock_Config();
 MX_GPIO_Init();
 MX_I2C1_Init();
 MX_SPI1_Init();
 MX_SPI2_Init();
 HAL_SPI_Receive_IT(&hspi2, (uint8_t*)spi_data_rx,10);
while (1)
 {
while(HAL_SPI_GetState(&hspi1)!=HAL_SPI_STATE_READY);
 }
}

 I write a file naming spi_slave.c and spi_slave.h to handle incoming data using interrupt, this is the .c one and the .h is empty:

#include "main.h"
#include "spi_slave.h"
extern SPI_HandleTypeDef hspi2;
#define spi_rxsize 10
char spi_data_rx[spi_rxsize];
uint8_t spi_rxcount = 0;
int spi_countAddr = 0;
int spi_countrxcplt = 0;
int spi_counterror = 0;
void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *hspi)
{
if(hspi->Instance == SPI2)
 {
 HAL_SPI_Receive_IT(&hspi2, (uint8_t*)spi_data_rx, 10);
 }
}
void HAL_SPI_ErrorCallback(SPI_HandleTypeDef *hspi) {
 spi_counterror++;
}

 Though I send 10 numbers from Arduino, I still miss some numbers when my stm32 reads them

 3. Some useful images:

STM32 clock configuration:

[waclawek.jan]

Try to lower the baudrate.

JW

[giangthewalkingman]

I tried lower the speed of Arduino clock about 2 or 4 times, but there is no use, the stm32 still misses the data.

[Saket_Om]

Hello @giangthewalkingman 

Please ensure that the GND (ground) pin of the Arduino board is connected to the GND pin of the STM32 board.

[giangthewalkingman]

Thanks, but the hardware connect doesn't matter. I connect both SPI and I2C, the I2C works okay, but the SPI is very problematic :(((

[Saket_Om]

Ensure that there is no synchronization issue between two devices. The slave should be ready to receive before the master start to transmit. 

Try to use DMA process in STM32 side.