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 is a writer specializing in hardware product reviews, comparisons, and explainers. He is very passionate about small form factor and single-board computers.
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For the price of only 10 (that’s ten) “esp32-c3 supermini” boards we get this board with almost identical height (22,25mm VS 22,52mm) and around 5mm less width (12,75mm VS 18,00mm).
Is it worth it? Only if space really matters…
supermini does not have equally capable power supply circuit and the availability seems subpar.
I would say that if your project requires the smallest possible board, it could be worth it. Think about enabling USB-C and/or WiFi for an existing device with very little room.For having had to hack with ESP8266 modules in the past that I had to place inside radiators, I could have paid $20 each to avoid spending hours on each device! Also the project shows what is possible. It might eventually be copied by some Chinese vendors who will make them in larger quantities at a much lower price.
And of course they, the Chinese, will also include a battery charger&connector, including the VBAT pin.
c3 usb it is only fixed function uart/jtag so not sure how good it is for “enabling usb-c” for other device, bu if serial is enough then yes
“It also includes a linear voltage regulator that provides up to 3.3V at 500mA”
I’m pretty sure it’s the other way around, ie ‘up to 500mA at 3.3V’.
Hi! There is an interesting option for a miniature board on the esp32-c3 with a round 0.71 display for less than 10 dollars. I ordered it and am already waiting for it.
https://aliexpress.com/item/1005007585001203.html