Uploading new sketch and having to unhook serial.

Hey guys. I have an arduino hooked up to a MediaMatrix Nion via serial. But when I want to upload a new sketch I have to unhook the TX cable or it wont upload the new sketch. Is there a way around this?


The USB interface is connected to the ATMEGA chip through a 1K risistor in both the TX and RX lines. Therefore you can try connecting the RX and TX lines of your device through a 1K before you connect them to pins 0 and 1.

This way it could stop them interfering with each other. However, you will be pumping "rubbish" into your device (a MediaMatrix Nion what ever that is) and if it responds with anything, then that could corrupt the messages back from the Arduino during a read and screw things up.

If that happens then you are best to use a double pole change over switch to isolate your device. It's simpler than unplugging the cable.