Here’s a slightly different way to check on the status of your laundry. Instead of checking if the machine is vibrating, or listening for sound, or pulling everything apart and hacking an ESP8266 into it, check the power that the machine is drawing. This is what [Scrand] did in his IoT dryer build.
The secret behind the hack is the Sonoff POW, a small device that sits in between the wall and the dryer. It has a relay in it that controls it, but, importantly for this hack, it’s able to measure the power consumption used by what’s plugged into it. By installing the ESPurna firmware on it, he can now use all the power of the firmware to control and monitor what’s connected to the POW. He wrote a PowerShell script to monitor the http server now running on the POW checking on how much power is being drawn by the dryer. When that power drops, the laundry is done, and in the case of [Scrand], a text is sent saying so.
When you’re sitting on the couch relaxing, why get up every five minutes to check your laundry when you can have it text you when you know it’s done? Then you can decide whether to get up and deal with it or just leave it until later. The whole reason ESPurna exists to begin with is to check on the status of the laundry. Or, you can go a bit overboard with this laundry room monitor.