Sorry guys another question from me.

The demo video shows a lady pressing a push button to ground on Tx Input pin1, which on the Rx latches an led on, so:

How do I mimic a 'single' button press to ground on Tx Input pin1 from a pic? do I:

Just set GPIO.0 = 0 'Pulls Tx pin1 LOW causes a Tx
then set GPIO.0 = 1 'pulls Tx pin1 High, from data sheet Tx Inputs pins are internally pulled high anyway
Or would the above cause two Tx's

Or do I:

Set GPIO.0 = 0 'Pulls Tx pin1 LOW causes a Tx
Then Change TRISIO = %00000001 'Set bit.0 to input and mimic a floating open switch Tx Inputs pins are internally pulled high