Posted on July 03, 2015 at 18:40Hi
I have succedded in transmitting a SPI message via DMA.
It sends the complete array whose length is specified by BufferSize (typically 100 in the examples). This value is assigned, e.g. to DMA BufferSize as DMA_InitStructure.DMA_BufferSize = BUFFER_SPI_SIZE ;
Someone know how to specify a different size during run-time by modifying the transmitter configuration (or another solution)?
I have tried
SPIx_TX_DMA_STREAM->NDTR = new_message_size;
SPIx_RX_DMA_STREAM->NDTR = new_message_size;
which is equivalent to
DMA_InitStructure.DMA_BufferSize = BUFFER_SPI_SIZE ;
DMA_Init(SPIx_RX_DMA_STREAM, &DMA_InitStructure);
DMA_Init(SPIx_TX_DMA_STREAM, &DMA_InitStructure);
in the transmitter (the receiver doesn�t know the length), but it doesn't seem to work.
I have read another post in which it is solved via NSS, but I would prefer not to using it.
Thanks in advance
#spi-dma-stm32-length
