The Epi C3 is a tiny ESP32-C3 development board with USB-C and an onboard antenna

The Epi C3 is a small development board based on the Espressif ESP32-C3 microcontroller with a USB-C connector for power and programming and an onboard ceramic antenna for wireless applications.

We have previously covered several tiny ESP32-C3 development boards such as the Microflex series, ESP32-C3-0.42LCD, the XIAO ESP32C3, and LOLIN’s C3 Mini and C3 Pico. The Epi C3 claims the title of the “smallest ESP32 dev board with USB-C and an onboard antenna.” It uses a Johanson ceramic antenna with a “surprising range for its size” and the USB-C port is sunk into the board to reduce footprint.

The ESP32-C3 microcontroller on the Epi C3 board is much more powerful than the 8-bit AVR chip on its predecessor, the Epi 32U4. The Epi C3, however, retains many of the older board’s protective features, including TVS diodes on the USB data lines and power input, a 500mA on the USB power line, and two ferrite beads for noise filtering. It also includes a linear voltage regulator that provides up to 3.3V at 500mA.

Epi C3 specifications:

MCU– Espressif Systems ESP32-C3FH4, single-core 32-bit RISC-V microcontroller @ up to 160 MHz; 400 KB SRAM; 4MB flash
Networking – 2.4 GHz WiFi 4 and Bluetooth 5.0 LE
USB
- USB-C connector for power and programming
- ESD and surge protection on USB data lines and power input
Expansion – 17x castellated headers (1.27mm spacing), with 12x available GPIOs, analog pins, reset, boot, power pins, and GND
Misc – Reset and boot mode switches
Power Supply
- Input voltage – 3.62V to 5.5V via VIN; ~5V via USB-C
- Linear voltage regulator – 600mA @ 3.3V
- 500mA polyfuse
- Ferrite beads for noise suppression,
Dimensions – 23 x 12.75 x 3.9 mm

The board has Arduino firmware preinstalled and preset with the ESP32-C3 dev module. The GitHub repository for the design files includes specifications for a variant with a U.FL antenna but it is not currently available for purchase

It is priced at $20 on Tindie and is currently available in limited stock. You can order the dev board with or without male headers.

Tomisin Olujinmi

Tomisin is a writer specializing in hardware product reviews, comparisons, and explainers. He is very passionate about small form factor and single-board computers.