ESP32 Tally Counter — pocket tally counter

Two buttons, a 0.91" OLED, an ESP32-C3 Super Mini and a 1000 mAh LiPo in a 58 × 58 × 22 mm 3D-printed case. Plain and ESPHome firmwares. Open source, generated from one script.

Source, build guide & README on GitHub

Case

58.0 × 57.6 × 22.1 mm closed · snap-fit lid · 4 parts, no supports

Interactive 3D preview

STL downloads

tally-base.stl (34 kB)
tally-lid.stl (121 kB)
tally-cap-plus.stl (41 kB)
tally-cap-minus.stl (39 kB)

Perfboard layout with every component, pin name and wire

Build it

50 × 50 mm single-sided perfboard (18 × 19 holes) · ESP32-C3 Super Mini · SSD1306 128 × 32 · TP4056 · 503450 LiPo

Perfboard layout (Özdisan 5x5 perfboard)
Wiring block schematic
Bill of materials, wiring table, assembly (README)

Wiring block schematic: power path and signals

Firmware

Same behaviour in both: click counts on release, hold both to reset, 30 s idle → deep sleep, count kept in flash

Plain .bin ESPHome .bin

Latest release — prebuilt binaries, also as OTA (.ota.bin)
firmware/plain/ — PlatformIO + Arduino, no radio
firmware/esphome/ — ESPHome, Home Assistant entities
Flashing from the browser (README)