Innovative PID Tuning Enhances Hot Glue Gun Safety

An Innovative Solution for Hot Glue Gun Users

The hot glue gun is a simple tool that features a power button, a heating element, and a power source, either battery-operated or plugged into the wall. Once activated, the heating element begins to heat up, allowing the user to extrude thermoplastic sticks known as "hot glue." However, without proper temperature control, the glue gun can overheat, causing burns or the melting of the material at the nozzle.

[Mellow_Labs] became frustrated with this issue after a prolonged session of hot glue usage and decided to enhance this tool by employing PID tuning, a concept familiar to users of 3D printers. By varying the power applied to the heater based on the desired temperature, as well as the integral and derivative, users can achieve far more consistent control compared to simpler algorithms.

In its implementation, [Mellow_Labs] utilizes a thermistor similar to those found in 3D printers and a MOSFET controlled by an RP2040 microcontroller, powered by the hot glue gun’s battery. Additionally, a small OLED display shows the temperature, which can be set using two buttons. This allows users to adjust the temperature to melt the adhesive while keeping it low enough to prevent leaks or third-degree burns.

Although the source code is not published, enthusiasts looking to replicate this project can find numerous examples of PID scripts available online. It is important to note that PID tuning is not limited to thermostats; it can also be applied in various thermal control contexts, such as in a charcoal grill using this control system.