[NRF51822QFAC][SDK11] How to recover Uart errors

[Lalit Kumar]

Hi,

I'm trying to interface SIM808 with nrf51822 over uart using nrf_drv_uart. Everything works well for some time, but then uart starts reporting error code 1, NRF_UART_ERROR_PARITY_MASK, for all transactions on uart. Re-initializing the uart doesn't correct it. Also the time after which error starts appearing is also random, varies from 15 minutes to 1 hour. The problem is not with the module as when the error occurs, I can still communicate with the module using external uart to usb. Here is what I think is relevant information:

• Baudrate is 115200
• Tx is blocking
• Listen to rx for 20ms
• Max transaction size for rx is 10 bytes

I can upload the code, if necessary.

Hoping for a positive response and thanks in advance :)

[Lalit Kumar]

I am getting some more errors now which are totally random, some occur after 12 hours. When I resolve the parity error, most of the times uart goes back to functioning properly, but sometimes it goes back to NRF_DRV_UART_EVT_ERROR with the error mask reported as 5. The list of error mask has only 4 entries in the documentation. I tried to create a separate question but the site always reports some internal error and am unable to post, so I'm posting here for now.

[Susheel Nuguru]

It should be in the nRF51 reference manual, you can download it from the infocenter from here.

Attaching the image for your convenience.

To flush RX buffer you need to read all the bytes in RX fifo. Unfortunately we do not have any example to handle it. you have to expand our last error handler for it. You can look at the reply to related thread here