We are having issues with UART communication on the nRF52840. Using a logic analyzer, we have found that the transitions happen too quickly. This causes the receiving MCU to read incorrect bits most of the time depending on where the transition lands. Is there a work around for this? Thanks.
try enabling pullups.
I am having problems understanding how "transitions happen too quickly", but it makes me think that you are talking about a situation where there are timing problems so that sampling happens too late, or similar? If so, I suspect one of two problems:
BAEE said:the transitions happen too quickly
What do you mean by that?
How about posting you LA screenshot to show what you mean?
How do you know it's the nRF being "too quick" - rather than other MCU being "too slow" ?
Or a bit of both?
I also believe it may be that the clock drifts too much between devices. However, unless we did something wrong, we attempted to select the crystal oscillator and it didn't seem to help the problem. Do you have some instructions for selecting the crystal oscillator?
It's still not clear what, exactly, your problem is!
BAEE said:the crystal oscillator
Which one - on the nRF, or on the other MCU.
UART comms requires that both sides of the link have accurate clocks.