Is it possible to "send" a serial command to the device itself to see the response? I have written a little routine based on a couple of serial sends and receives and want to see if that works out like I want.
EDIT:
I have a device (an AVR with arduino boot loader) and as part of my program, the device exchanges phrases with peripheral devices over a serial connection. Since I have right now just the arduino itself and can't really test, if at least the logic behind the serial part of works out, I would like to get serial commands from somewhere and trigger 'continuous talking', so I want to monitor the response behavior of my module, if it gets a certain command (stability reasons). Instead of waiting for a second device, is it possible to "link the TX/RX line to itself" internally or externally to test my program with itself?