Solved
Issues with SPI comms between two STM32s
I'm trying out simple SPI comms between two STM32s. The TX is STM32F407 and the RX is STM32G070. The data that I seem to be receiving is different from what I'm sending. What am I missing here?
For the RX, I've set the NSS to software. I've configured the 'chip select' to be an external interrupt on the falling edge. In the ISR I receive the bytes from the TX. This is what the code for the RX looks like. SPI1 is configured as full duplex slave.
/* USER CODE BEGIN PV */
uint8_t spi_rx_buffer[8] = {0, 0, 0, 0, 0, 0, 0, 0};
/* USER CODE END PV */
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/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Falling_Callback(uint16_t GPIO_Pin)
{
if (GPIO_Pin == SPI1_CSN_Pin)
{
if (HAL_SPI_Receive(&hspi1, spi_rx_buffer, 8, HAL_MAX_DELAY) != HAL_OK)
{
Error_Handler();
}
}
}
/* USER CODE END 4 */For the TX, SPI is configured to be a full duplex master with software chip select. With the 64 divider, the data rate configured as 1.3125 Mbit/s. In the TX, I'm simply sending two buffers each of 8 bytes at a time. The code for TX is as follows:
/* USER CODE BEGIN PV */
uint8_t spi_tx_buffer1[8] = {0, 1, 2, 3, 4, 5, 6, 7};
uint8_t spi_tx_buffer2[8] = {8, 9, 10, 11, 12, 13, 14, 15};
/* USER CODE END PV */
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/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
HAL_GPIO_WritePin(SPI1_CSN_GPIO_Port, SPI1_CSN_Pin, GPIO_PIN_RESET);
HAL_SPI_Transmit(&hspi1, spi_tx_buffer1, 8, HAL_MAX_DELAY);
HAL_GPIO_WritePin(SPI1_CSN_GPIO_Port, SPI1_CSN_Pin, GPIO_PIN_SET);
HAL_Delay(5000);
HAL_GPIO_WritePin(SPI1_CSN_GPIO_Port, SPI1_CSN_Pin, GPIO_PIN_RESET);
HAL_SPI_Transmit(&hspi1, spi_tx_buffer2, 8, HAL_MAX_DELAY);
HAL_GPIO_WritePin(SPI1_CSN_GPIO_Port, SPI1_CSN_Pin, GPIO_PIN_SET);
HAL_Delay(5000);
}
/* USER CODE END 3 */The data that I receive is as below,
