UART resets the chip when sending new line

RE: UART resets the chip when sending new line

Stefan Birnir Sverrisson — Wed, 31 Aug 2016 14:19:54 GMT

Are you using the default SDK 11 UART example otherwise?? My main code looks like this, which seems to be working fine with optimization level 3:

printf("\n\rStart: \n\r");

uint8_t p_data[4] = {0x41, 0x54, 0x0d, 0x0a};

for (uint8_t i=0; i<4; i++) { while (app_uart_put(p_data[i]) != NRF_SUCCESS); }
for (uint8_t i=0; i<2; i++) { while (app_uart_put(p_data[i]) != NRF_SUCCESS); }
	
while (true) { }

I can receive all the characters on the UART peer side. Perhaps it could help to see trace of the UART lines when this data is sent (RXD,TXD,RTS,CTS), perhaps that will provide some hints.

RE: UART resets the chip when sending new line

nirmal@nordic — Wed, 31 Aug 2016 14:04:47 GMT

This is strange !!!!! Yes I am using nRF51 - DK.... But I could not make it working on Level 3 ...

RE: UART resets the chip when sending new line

Stefan Birnir Sverrisson — Wed, 31 Aug 2016 13:23:34 GMT

I was actually running this with Level 3 optimization, but it works fine. Im running this on nRF51-DK. Are you using the same?

RE: UART resets the chip when sending new line

nirmal@nordic — Wed, 31 Aug 2016 13:09:15 GMT

Hi, Thank you for your answer... But I found issue was running with Level3 Optimization...

As soon as I switched to Level 0 Optimization...It worked fine.

RE: UART resets the chip when sending new line

Stefan Birnir Sverrisson — Wed, 31 Aug 2016 13:05:29 GMT

I insert your snippet code into the uart example in nRF5 SDK 11.0.0 and it works fine. I can not reproduce the problem. By default, the nrF51 resets upon application error. Check if you can capture an error code in the debugger instead of resetting the nRF51, as described here. This thread could also be helpful for debugging.