I work with the ConnectCore Wi9p9215. It has 4 UARTs. So I have implemented 3 DB9 in RS232 (serial A, B, C) and 1 TTL link (serial D). I have configured 4 UARTS in 2 wires with the NET+OS software.
Only one DB9 works (serial
I don't know why other link doesn't work. I know that all TTL signals go to the module but it doesn't read datas.
Have you got an idea ?