4 relay switch, 1 with timer
I wanted some easy to reach wall sockets on my desk, to have power for my projects nearby.
As I am using my soldering iron a lot and sometimes forget to plug it out, I wanted to have a timer on one of them.
This project has 4 relays (a 4 relay module - no sketch in Fritzing I'm afraid) turning on and off via push buttons.
The first relay has a timer and an extra button. 3 LED's are used to display the state of the relay. Red is off, blue is on and green lights up when time is nearly finished. The extra button resets the timer.
The sketch contains the breadboard set up and the Arduino code. The code is easy to edit. Use interval to set the total time (in milliseconds). intervalReset is set to three quarters of the total time and can easily be adjusted to your needs.
You can use as many relays as you have free ports on Arduino. Just keep in mind: use external 5 volts on relay switch (JD-VCC) and common Ground!
Enjoy and please let me know what you think!