Posted on May 17, 2011 at 13:10Hello,
I'm trying to get the DMA to work for the UART1TX.
I'm using freeRTOS and need my tasks to stay active all the time.
I have looked at the example given with the firmware, I have configured the DMA for UART1, tried to send data once, and it works, but my problem is what should I do to get it to work the next time.
I mean, i have written a function RS232_Write(char* c) that fills my TXbuffer with the requested data, of course after waiting the DMA1_FLAG_TC4 to be ready, then i reconfigure the length of the data to be sent, reinitialise the DMA
DMA_InitStructure.DMA_BufferSize=l;
DMA_Init(RS232_DMA_CHANNEL, &DMA_InitStructure);
//Activation de DMA TX request
USART_DMACmd(RS232_UART, USART_DMAReq_Tx, ENABLE);
// Active DMA1 Channel4
DMA_Cmd(RS232_DMA_CHANNEL, ENABLE);
l is the length of the data.
The problem is in this turn nothing hapens and i dont get anything on the screen!
Would someone help me please?
Thanks
