My washing machine is located in the basement. Unfortunately, the time data displayed on the front panel is always inaccurate. So instead of constantly running down the stairs and checking if the laundry is done, I decided to connect the washing machine to my LAN and extend it’s features by a simple http server. This is what I needed for it:

* 1 arduino uno
* 1 ethernet shield
* 1 opto-coupler (CNY17)
* 1 perfboard
* 1 resistor (150 Ohm)