UART break

RE: UART break

Ole Bauck — Wed, 21 Sep 2016 12:53:58 GMT

You can shorten the 21 microseconds a lot. The SDK driver actually starts and stops the transmission for every byte, which is not efficient at all. If you look at the Reference Manual part 29.4 this is not necessary. You can write your own driver to send the bytes.

Actually what I said in the last comment is not the correct time to measure. The time between ENDTX interrupt and TXD being set is about 24us which reflects the total time the nRF51 is doing the processing.

RE: UART break

Sascha — Wed, 21 Sep 2016 11:36:56 GMT

Thanks for your answer. Ok, i thought so. So, there is no way to shorten this 21 microseconds? Think its much time, if i will send a couple of data, compared to the cable variant.

RE: UART break

Ole Bauck — Wed, 21 Sep 2016 11:04:52 GMT

The 21 extra microseconds you see when using nRF51 is due to processing (it is the time between the ENDTX interrupt and the STARTTX task where a new byte is being transferred). It should not be a problem however as each byte starts when the line goes low.

Unless the the time it takes to receive all the bytes matter this should work and I would try to look for other reasons it is not working.