STM32F072-DISCO UART DMA doesn't work

[Leonelf]

Posted on February 20, 2016 at 18:28

Code is in the Attatchments.

I'm trying to periodically send data over SPI and to receive data over USART. Sending over SPI w/ DMA works. But the USART DMA doesn't work. I can send whichever data I want, but the DMA wont trigger an interrupt. Disabling DMA and using UART interrupts works, the interrupt fires as soon as USART receives data, so my data or USART aren't to blame. 

Is there something wrong with my init routines? Or something else?

[Tesla DeLorean]

Posted on February 20, 2016 at 20:54

Make sure things like this are resolving to addresses, it looks ok, but the cast will hide any objections the compiler might make

DMA1_Channel3 ->CMAR = (uint32_t) buffer[!currentBuffer][layer];

This might be more explicit

DMA1_Channel3 ->CMAR = (uint32_t) &buffer[!currentBuffer][layer][0];

Check that the DMA isn't flagging some kind of error condition, and that your reinitialization of the DMA is sufficient to restart it.

[Leonelf]

Posted on February 20, 2016 at 23:17

I looked into the DMA flags. The error flag is 0, so no error :(

[Leonelf]

Posted on February 26, 2016 at 22:42

bump

[waclawek.jan]

Posted on February 27, 2016 at 17:12

What is the value of  SYSCFG_CFGR1.USART1_RX_DMA_RMP?

JW

[Leonelf]

Posted on February 28, 2016 at 10:42

I assume you meant SYSCFG_CFGR1_USART1RX_DMA_RMP? Its value is 0x400