Hackaday Supercon has a few of the greatest badges in your complete maker/hacker scene and 2025’s badge maintained that legacy. It was principally a handheld laptop constructed round an ESP32-S3 and Seeed Studio’s Wio-SX1262 LoRa transceiver module. And, after all, it had the all-important SAO (Commonplace Add-On) port. Justin Miller took benefit of that port to flip his Supercon 2025 badge right into a synthesizer.
The {hardware} for this synthesizer is about so simple as it might presumably be. It’s actually only a single element: a piezo buzzer. One leg goes into GPIO Pin 1 on the SAO and the opposite leg goes into the bottom pin. Which may simply make this the SAO with the shortest BoM in historical past—on the very least, it needs to be tied for first place.
As a result of the {hardware} is so unbelievably primary, the synthesizer performance all comes all the way down to the software program. Miller programmed that in MicroPython, which is what the Supercon 2025 badge was designed for. It outputs a PWM sign on Pin 1 with a frequency that matches the chosen word. He then created a pleasant GUI utilizing LVGL. That exhibits piano keys with labels for the corresponding keyboard buttons. The person will get these keys, plus the choice to change between octaves.
The Synthy Add-On was such at hit at Supercon 2025 that Miller was invited to the stage to provide a dwell demonstration. If in case you have the badge and a piezo buzzer laying round, you may strive it for your self by grabbing the Python code from Miller’s GitHub repository.
