12C671 - GP3 problem

[aratti]

With reference to your schematic, I am sure you have mistaken in drawing it, while the hardware is correctly wired, otherwise you will short the 12 Volts as soon as you connect it to the circuit. ( see the snap posted and compare it with your circuit)

As far as the code is concerned, I would place a delay below the label send

send:
PAUSE 10
if gpio.1=0 then
serout ToTx,N2400,["G0"]
Low ToTx
pause 10
endif

Al.