Actually i have a RF Alert system controlled with one Arduino Mega interfaced with an LCD Touch Screen 4D uLCD-43p (Just a interfaced with serial Output, and a few digital pins) http://www.4dsystems.com.au/product/1/11/4D_Intelligent_Display_Modules/uLCD_43/.
I am trying without successful Implement a external interrupt with the digital pins of the screen. To make an almost sync serial communication. The function inside the interrupt must be larger enough to understand the incoming data. Until now i can't make it works and I've only seen examples of interruptions to read encoders.
Any idea to made this work?