Hello,
I use an Arduino Mega card. It is supposed to have 6 attachInterrupt pins on pins D2,D3, D18,D19,D20 and D21. I should be able to have two attachInterrupt which is what i need.
However i use an Adafruit Wifi shield, which uses D3,D4 and D5 for SD storage ; the attach interrupt pin on D3 doesn't work .
Plus i use a Chronodot RTC which needs I2C buses on pin D20 and D21 on Arduino Mega.
Therefore i tried using D2 ( which works), and D18 and D19, which doesn't. Those are marked TX1 and RX1. I'm new to micro-controllers so i don't understand exactly what it is and when i use it . I guess it's used when there is a serial communication with my computer but i'm not sure.
My question is : are the RX1 and TX1 activated when i use the serial port? are they disabled when i don't or the fact that i use i2C and SPi communication makes them be activated anyway?
Do you have a solution ?
Thank you very much