Rookie error. Unable to Upload sketch to Uno R3

I uploaded a simple sketch to test serial comms. It just sends out "Hello World" continually. It works fine, got my RS232 module and serial cable sorted.


I cannot now upload any other sketches to the Uno due to the transmit pin continually sending out the "Hello World" message. The program does not have any delays and the transmit line starts up straight away.

I have tried resetting the Uno at different times whilst trying to Compile/Upload but have not had any luck yet.

Does anyone know a way around this issue other than buying another controller?


Thank you. You were quite right. Disconnecting the RS232 module did it.

Because I was only using the transmit output I was forgetting that the receive line would/could be held by the RS232 module.

Disconnecting the just RX between the RS232 module and the Uno is enough to allow the Upload to take place.

Thanks again