I'm trying to get the LPC845 to run the USART with DMA on TX, but without luck. Any chance for an experts code review I have attached the c file.
Tested on a LPCXpresso845-max.
What I did:
1) I have imported the uart terminal and transfer dma demos from the SDK. Both work as expected.
2) I wated to mod the terminal demo to send a string using DMA. Change done:
2.1) removed the IRQ part
2.2) copied lots of the DMA demo (see lines 33 to 66 in attached)
2.3) removed the "pingpong" descriptor (see line 39)
2.4) change `uart->RXDAT` to `uart->TXDAT` and swapped source and destination (see line 60)
2.5) change from `kDMA_PeripheralToMemory` to `kDMA_MemoryToPeripheral` (see line 61)
2.6) removed to creation of the pingpong descriptor and added a new single descriptor (see line 64 and 65). I have no idea what to set the `next` descriptor to, I have tried setting it to the same descriptor and NULL. Neither works.
2.7) Added `DMAConfigutation()` and `StartTransfer()` to the main function, just before the infinit loop. (see line 93 and 94)
What I expected to see: "Hello, world!" printed in my terminal.
What I actually see: The project builds and runs. I can debug it and single step the code. But nothing in printed in the terminal.