A tiny computer.
Nothing you don't need.

dummy is a minimal ESP32-C3 dev board: 18 parts, USB-C, WiFi and Bluetooth. Plug it in, write ten lines of code, and it does what you say. No drivers. No setup. No mystery.

3D render of the dummy dev board
18components
160 MHzRISC-V CPU
4 MBflash storage
25×52mm, smaller than gum

Specs

Everything on the board earns its place. Here's what you get.

CPUESP32-C3-WROOM-02-N4

Single-core RISC-V at 160 MHz, 400 KB RAM, 4 MB flash. The same chip family found in millions of smart-home devices.

RADIOWiFi + Bluetooth LE 5.0

2.4 GHz WiFi (join a network or broadcast your own) and BLE. The antenna overhangs the board edge on purpose — clear signal.

USBUSB-C, wired straight to the chip

No USB-serial translator chip. Power, programming, and serial debug over one cable. Shows up the moment you plug it in.

POWER5 V in, 3.3 V logic

AMS1117 regulator on board. Feed it from USB, a power bank, or the 5V pin. Code lives in flash and runs on any power source.

IO15 GPIO on 20 labelled pins

Two 10-pin headers, every pin labelled on the silkscreen. ADC, I2C, SPI, UART, PWM — sensors, motors, lights.

SAFEUn-brickable by design

RESET restarts the board. Hold BOOT while plugging in and the chip waits quietly for new code - recovery is always possible.

The board

Matte black, machine-assembled, every part placed by robots.

top view of the board
top — brain, buttons, LED, labels
bottom view of the board
bottom — clean routing, nothing hidden

Pinout

Ten pins a side. Also printed on the board itself, because nobody remembers.

J2 — left
GND ground
EN enable / reset
IO4 gpio · adc
IO5 gpio · adc
IO6 gpio
IO7 gpio
IO8 gpio · blue LED
IO9 gpio · BOOT
3V3 3.3 V out
5V 5 V in/out
J3 — right
IO0 gpio · adc
IO1 gpio · adc
IO2 gpio · adc
IO3 gpio · adc
TX uart tx · IO21
RX uart rx · IO20
IO10 gpio
GND ground
3V3 3.3 V out
5V 5 V in/out

Under the hood

The front copper layer, exported straight from the design file. This is the actual circuit — every track drawn on purpose.

front copper layer artwork