Communication

MCU Communication Peripheral Guide

UART DMA (Recommended for continuous RX)

// Circular DMA receive (never stops)
uint8_t rxBuf[256];
HAL_UARTEx_ReceiveToIdle_DMA(&huart1, rxBuf, sizeof(rxBuf));
__HAL_DMA_DISABLE_IT(huart1.hdmarx, DMA_IT_HT); // Disable half-transfer if not needed

void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size) {
  // Process rxBuf[0..Size-1], restart DMA
  HAL_UARTEx_ReceiveToIdle_DMA(huart, rxBuf, sizeof(rxBuf));
}

SPI Full-Duplex

uint8_t txData[4] = {0x80, 0x00, 0x00, 0x00}; // Read register 0x00
uint8_t rxData[4];
HAL_GPIO_WritePin(CS_GPIO_Port, CS_Pin, GPIO_PIN_RESET); // CS low
HAL_SPI_TransmitReceive(&hspi1, txData, rxData, 4, 100);
HAL_GPIO_WritePin(CS_GPIO_Port, CS_Pin, GPIO_PIN_SET);   // CS high