UART C Code not work

[adamS]

Hi,
I want to use uart to communicate with some device,
The C code I use is copy from redpitaya doc web page.
https://redpitaya.readthedocs.io/en/lat ... /uart.html
when I run this code, I receive nothing,
the terminal print "AGAIN!" continuously, means data still not coming.

Below imgur link shows TX and RX signal image captured by scope,
Rx(green) signal lags Tx(yellow) signal for about 25ms.
https://imgur.com/a/bGchYzx

I checked if I short Tx to Rx pin,
then these two signal appear in the same time,
and this C code works fine.

I appreciate any help:)

[adamS]

Hi,
the problem is solved,
I follow the steps in below website
https://stackoverflow.com/questions/379 ... -from-uart