Dryer Monitoring System
The Dryer Monitoring System is a real-time solution designed to monitor the operational status of a dryer using an ESP32 microcontroller, limit switches, and a web-based interface.
How does it work?
The system is pretty simple and consists of these parts:
- ESP32 Microcontroller: Core processing unit that reads switch states and communicates with the server.
- Limit Switches: Three switches placed around the dryer dial to detect its ‘off’ position.
- Node.js/Express Server: Handles communication with the ESP32, serves the web interface, and logs dryer status data
Why does this exist?
I wanted a way to check on my laundry status without going to the basement everytime. I could just look at at my phone and see the dryer status.
I was also collecting dryer usage data in order to predict dryer usage and recommend optimal use time.
Is the system still up?
Sadly, no. It ran for a couple months, but had a design flaw. Limit switches (the type that 3D printers use) were being used to detect the position of the dryer dial. Turns out that, this was not a very robust solution.
When people would turn the dryer dial, their fingers would inadvertently hit the limit switches. Over time, this action would move the switches out of place. Consequently, this would affect the detection capability of the system.
I had come up with a better detection mechanism to fix it but never came around to implement it. Instead of using limit switches, an ultrasonic sensor could be used for detection. It would be placed at a distance (about 20 cm) from the dial and hence would be out of the way.
The detection logic would be as follows:
if(distance <= x){
// dryer is off
}
Otherwise if the distance is greater than x (i.e x+y), the dryer is on.
This implementation was not tested though.
Source code
The source code for the system can be found here.