Everything posted by sbela
I have a nanopi m4 and I want to use the /dev/ttyS4 (UART4) for communication, but only the RX is working, and the TX does not, but when I set the GPIO nr. 40 (the TX pin) to output through sysfs I can change the voltage level from high to low and back... Please help, what am I missing here, that I can not transmit anything ? I am using the latest friendlycore.