Q: How to use STM32 DMA controller efficiently for UART SPI and ADC?
Answer
DMA (Direct Memory Access) offloads data transfers from the CPU. For UART use DMA with a circular buffer for RX to avoid losing bytes during interrupt latency. Configure DMA in normal mode for TX with transfer complete interrupt. For SPI DMA handles both TX and RX simultaneously. ADC with DMA can sample at rates up to 2.5 MSPS without CPU intervention – use a timer trigger to start conversions at precise intervals. Always set correct data width and configure peripheral-to-memory vs memory-to-peripheral direction. DMA stream-to-stream transfers on STM32F4 support FIFO mode for burst transfers. Watch for DMA priority conflicts when multiple streams are active simultaneously.
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