What to do with APP_UART_COMMUNICATION_ERROR?

[dorafmon]

Hi, I am working with app_uart module and during the reception process sometimes there will be APP_UART_COMMUNICATION_ERROR event generated, my question is why there is such errors? And is it possible for us to do some error recovery?

BTW, if we have both BLE and UART running on the nRF51822 chip, what is the highest Baud Rate the chip can offer?

[Ole Morten]

When such error occurs, you can read out the corresponding error code in the structure. This value corresponds to the value of the ERRORSRC register in the UART peripheral, that explains what went wrong.

If you run the softdevice, it is most likely an OVERRUN error, which will happen if the other UART device sends too much data while the CPU is blocked by the softdevice. Depending on the nRF51822 chip revision used, the UART buffer is either 2 or 6 bytes.

Using flow control on the latest chip revision, with 6 bytes buffer, should eliminate this problem. Flow control should help also on the previous revision, but some UART implementations will manage to overflow the buffer before flow control is handled.

[dorafmon]

Is there any chance I can do a error recovery here?

[Ole Morten]

This isn't really possible to say anything about, since it will depend on the exact error that happens and the application. If it is in fact an OVERRUN error as I suspect, bytes have been lost, so what to do with that is really an application choice.

[Jeffrey Krinsky]

How would we go about reading the ERRORSRC register in the UART peripheral?

[wangyong]

It might be helpful by adding this nrf_gpio_cfg_input(RX_PIN_NUMBER, NRF_GPIO_PIN_PULLUP); to uart_init function