THOTCON 0xB Badge
Half NES controller, half circus ticket
The theme was Bozo the Clown. The badge is an NES controller crossed with a circus ticket. It plays the circus song, and when you tilt it, it turns into a synthesizer.
Specs
- Event
- THOTCON 0xB, Chicago, October 8–9, 2021
- Chip
- ESP32
- Lights
- Reverse-mount LEDs behind the lettering and buttons, on an IS32FL3731 driver
- Controls
- Capacitive touch buttons, accelerometer
- Sound
- Piezo buzzer
- Network
- Wi-Fi, IRC, serial
What it does
It plays Entry of the Gladiators, the circus song everybody knows, and it will rickroll you. Tilt the badge and the accelerometer drives the buzzer, so the angle you hold it at sets the pitch.
The LEDs are mounted on the back of the board and shine through it. The big THOTCON letters glow from inside, and each touch button lights up when you press it. The badge also gets on Wi-Fi and talks over IRC.
How it was built
The event artist set the shape and the art. Rob Rehrig joined the badge team this year, after winning a gold badge at 0xA, and did the schematic, board layout, and drivers. We stayed on the ESP32 so we could reuse circuits and code from the year before.
One fix came late. Freeing up a pin for a touch button left badges booting into the wrong mode on battery power, and nobody caught it until the design had gone out for production. Rob worked out a one-resistor fix with the assembly house before the badges shipped.
We taught a workshop on hacking the badge at the conference. The sample sketches are on GitHub.
Who made it
- Jay Margalus, Rob Rehrig, and Rudy Ristich.
- Shape and art by the THOTCON event artist.