CubeCell PIN 14 RX

How do I code Cubecell to receive messages via PIN14? I have another board TX attached to the Cubecell PIN 14 (RX). I don’t receive any messages. However if I use my esp32 lora heltec board (rx pin) I can see the serial msg’s coming from the other board. In my code I tried INPUT_PULLUP but it didn’t compile. I also tried pinmode input high/low combinations but this did not work either. When I type something in the serial window I see the output in my Cubecell but through the PIN14 nada. Ideas? thanks in advance, james

James, I seem to get the same behaviour. I tried to read an external sensor through pin 14, using serial connection in Arduino. AFAIK the cubecell only features 1 UART which is also used for the USB connection. I also tried several things but never received anything on pin 14. Tried with and without parallel USB connection.
I assume you also used serial.begin() and
PS serial monitor via USB works fine in both directions