IMPORTANT: Install the following sketch on your Arduino to use AutoArduino: https://github.com/joaomgcd/AutoArduino-Sketch/blob/master/pins.ino

STEP 1 - CONNECT LED TO ARDUINO

• Create a circuit like in this tutorial
• Connect negative (shorter) end of the LED to GND on the Arduino
• Connect positive (longer) end of the LED to Pin 4 on the Arduino

STEP 2 - CREATE PROFILE

• Create a new profile with the AutoArduino Input Changed event condition
• Select Pin 3 under Pins

This will make this event trigger every time a change in pin 3 is detected

• Select LOW and HIGH under Values

This will make this event trigger both when the pin is HIGH or LOW

• Accept settings and create a Task associated with this profile

STEP 3 - SHOW STATE CHANGE

• Add a flash action and set the text to %aapin %aastate

This will show the number and state of the pin that changed in this event. The state can be either 0 if the pin is LOW or 1 if the pin is HIGH.

STEP 4 - CHANGE LED STATE

• Add an AutoArduino Write Pins action
• Click on Direct Command
• Write the text d4,%aastate;

This is a command that will change pin 4 to whatever state is in the %aastate variable. So, if %aastate is 0, pin 4 will be set to LOW, if it's 1, pin 4 will be set to HIGH. Since a LED is connected to pin 4 it'll change the state of the LED. If you want to learn more about the command format check the little icon at the top right of this screen

• Back out of Tasker to Save your new profile

STEP 5 - TEST

Make sure you are connected to your Arduino with AutoArduino so you can receive events. Check step 2 here to learn how to do that.

Now when you press the button it'll set Pin 3 to LOW which will make the AutoArduino event you just configured fire, which in turn will set Pin 4 to LOW, making the LED turn off.

On the other hand, if you release the button it'll set Pin 3 to HIGH which will set pin 4 to HIGH making the LED turn on!