For those of us in the northern hemisphere, summer is still in full swing. If you’re still planning a summer bash or two before fall hits, you might want to take a look at this awesome pellet smoker hopper level monitor created by maker and developer Joe Pecsi. Using our favorite microcontroller, the Raspberry Pi Pico, he’s able to monitor his pellet smoker’s hopper level and keep track of it with a mobile app.
The concept is simple but also a super effective way to monitor the pellet level in your smoker without having to get up and check. It relies on an ultrasonic sensor to measure the pellet level which is then automatically reported through a web-based app. This can be checked from any device with a browser like a PC or a smartphone.
Not only does the Pico accept input from the ultrasonic sensor, it also hosts a web server. The web app data is shared using MQTT over WiFi. This is what enables you to check the hopper level remotely. The mobile app has a few settings, as well, that you can use to make adjustments including an option to calibrate the sensor.
Pecsi was kind enough to share a complete breakdown of the hardware used in his hopper monitor setup. He’s relying on a Raspberry Pi Pico W for its wireless support and an HC-SR04 ultrasonic sensor. In addition to these boards, he also created a PCB from scratch just to make the setup a little more professional. Plans are in the works to create 3D printed housing for the unit as well as a battery pack.
The software used in the project has also been made open source. You can find the various repositories used in its creation over at GitHub. It includes the Python scripts used to operate the Pico and everything you need to check out how the mobile app works. According to Pecsi, he’s using Flutter to operate the web app.