Serial.Begin won’t give you much of an error as it is more related to the port on the UNO as opposed to what it connected to. It won’t show an error if the connection speed is wrong.
Have you confirmed if 115200 is the correct speed?
Is there any particular “wake up” that the Nomad is looking for?
Perhaps another issue may be the USB mode on the UNO. I am guessing here, but natively it is running in “Client” mode as it talks to the PC which is in “Host” mode… In order to control something from the USB port it needs to be in “Host” mode. I am not sure the UNO is capable of that.
I seem to remember this, anyone correct me if I am wrong:
In Host mode the device controls the conversation and will either send data or ask if the client has anything to say. Client mode devices will only talk when asked by a device in Host mode.
So if the UNO is in client mode it’s not going to work… (Thats just theory in my mind as I have never tried this )
I do have a spare controller so I might try this with an ESP32 device I made that has a native FDDI USB chip onboard.
For reference, I connected my Mac to Nomad3 and used IONinja (serial port monitor) in order to send/receive data. I confirmed 115200 is the proper speed. Using this method, I can send commands to Nomad3 properly.
I also sent “^X” to initialize Normad 3 from UNO instead \r\n\r\n but the result is the same.
The problem is not sending code itself, it is how to establish the connection and wake up Nomad 3 I guess (I might be wrong