Odd behavior with nRF52810 UART transmission

RE: Odd behavior with nRF52810 UART transmission

Jared — Fri, 15 Nov 2019 09:20:19 GMT

Hi,

This can happen to the best of us! :) The most important thing is that you found the solution and returned with it for others to see if they have the same issue.

best regards

Jared

RE: Odd behavior with nRF52810 UART transmission

eBrock — Thu, 14 Nov 2019 16:22:43 GMT

OK, now I feel stupid. I didn't have enough resolution on the scope sampling, so it wasn't seeing every TX.

Increasing the samples per second now reveals proper transmission.

RE: Odd behavior with nRF52810 UART transmission

eBrock — Thu, 14 Nov 2019 15:38:29 GMT

Yes, I tried waiting for the ENDTX flag and still got the same behavior.

A couple details I forgot to include:

Declaration of the buffer variable:

static volatile int8_t uarte0TxBuffer[8]; // UARTE0 Tx buffer

SES version 4.30a

nRF52 SDK 15.3.0

I attached a scope plot. As you can see, the messages are sent at random times, but synchronized with the loop timing.

It's like the STARTTX task is not being triggered every time.

RE: Odd behavior with nRF52810 UART transmission

Jared — Thu, 14 Nov 2019 12:26:03 GMT

Hi,

You should wait for the nRF to generate ENDTX event that indicate that the transfers is complete by adding this after you have started the transfer:

  while (NRF_UARTE0->EVENTS_ENDTX == 0)
  {
  }

regards

Jared