nRF52 uart problems with errors 4 and 8

[mbozic]

Hi,

I have a Rigado BDM-300 (nRF52832) on a small custom board. Using SDK 13.1 with SD132 v4.0.2.

I've taken a template project and adjusted it to my needs. I can get my services there, connect to the board with mobile device, etc...so I know board and application in that state work. I have experience with nRF51 so all that was not a problem.

But, when trying to add UART things go haywire. I've used UART setting from "ble_peripheral\ble_app_uart" example, FIFO is used.

After UART is initialized it throws APP_UART_COMMUNICATION_ERROR in it's handle. Errors I get from p_event->data.error_communication are 4 and 8, first 4 is thrown, then 8 immediately after.

I've disabled nrf logging (not using uart or RTT for nrf log) and I've enabled RTT, so uart channel should not be used for logging.

Is it possible that NRF_LOG calls in other files could be messing with uart? I'm out of ideas, I will try to configure NRF_LOG to use RTT and see what happens, but everything I've tried so far failed to work. I've also tried to disable EasyDMA and use only legacy but I get the same errors.

Thanks!

[FormerMember]

If there is no 32 kHz crystal connected to pin 0 and 1, there shouldn't be any problem to use those pins as GPIOs.

In your code, do you have set the LFCLK crystal source to the internal RC oscillator? If not, could you do so, and check if it changes anything?

[mbozic]

Ble UART example is not working for me at the moment, it stops at Segger_RTT.c at line 304: p->aDown[0].WrOff = 0u; RTT version is 6.16j. For default version of Segger RTT which comes with SDK, code hangs at line number 187. Tried to disable RTT but then it stops at SD initialization, which is weird. Anyways, we'll probably just change PCBs and use some other pins which are not 0 and 1, which will solve our problem.