ESP32-C3 SuperMini

Not yet tried on real hardware

Profile and firmware are built (Bluetooth floods through NimBLE, deep sleep on the GPIO wake path) but it has not been flashed onto a real board yet. Expect surprises, and please report them.

Chip	ESP32-C3FH4
Dimmers, servos & motors	6 PWM channels (a motor takes 2)
LED strips (WS2812)	up to 2
Battery	no built-in sense; power it from USB or a 5 V supply, or add a two-resistor divider to read a battery (Battery props)
Firmware	esp32-c3-supermini, install it from your browser

Pinout

Note

Different sellers lay this board’s pins out in a different order, so there is no drawing here. Go by the GPIO numbers printed on the board and the table below.

The seller-style pinout with photos: esp32.co.uk.

Versions of this board

“ESP32-C3 SuperMini” is a board format, not one product, and sellers’ versions differ. Check these on the board in hand:

• The common black board has a plain blue LED on GPIO 8 (it lights when the pin is LOW) and a ceramic antenna. Its WiFi range is often reported as poor because of the antenna layout, and it varies from batch to batch. Since the mesh uses the same radio, expect weaker links than from a DevKit. People report that soldering a 31 mm wire to the antenna’s feed pad helps a lot.
• The red SuperMini Plus has a U.FL socket for an external antenna and a WS2812 pixel on GPIO 8 instead of the blue LED (some also keep the blue LED on the same pin). Assign GPIO 8 as LED strip with 1 pixel to use it.
• Header order differs between sellers. Go by the GPIO numbers printed on the board.

Which pin for what

The console marks these with ★ when you assign pins. They are advice. Any pin that can do a job is allowed.

To connect…	Use	Why
Servo	4 5	Quiet at power-up, so nothing twitches while the board boots.
DC motor (H-bridge IN1/IN2)	6 7	A quiet pair side by side for IN1 / IN2 — a motor never lurches at boot.
Relay / on-off output	20	Quiet at power-up, so a relay never clicks on during boot.
LED strip (WS2812)	10	Any output can drive a strip; the C3 has two strip engines (RMT), so two strips at most. 3.3 V board — use a 74AHCT-type level shifter for 5 V strips.
LED dimmer (PWM)	2 8 21	The boot-quirk pins — a flicker at power-up doesn’t matter for a light. 8 is the onboard blue LED (on = LOW) on the common board.
Sensor / button input	0 1 3 9	GPIO 0–5 are the low-power pins: the only ones that can wake the board from deep sleep on battery. All have internal pull-ups, so buttons need no resistor. 0–4 also read analog.

Every pin

Pin	GPIO		Can be	Note
0	0	✅ good	input, output, pull-up, pull-down, analog, wakes from sleep
1	1	✅ good	input, output, pull-up, pull-down, analog, wakes from sleep
2	2	⚠️ caution	output	STRAPPING: must be HIGH at power-up or the board will not boot. Outputs only, and nothing that holds it low at reset (a PIR’s output idles low)
3	3	✅ good	input, output, pull-up, pull-down, analog, wakes from sleep
4	4	✅ good	input, output, pull-up, pull-down, analog, wakes from sleep	also JTAG TMS — harmless for anything this board does
5	5	✅ good	input, output, pull-up, pull-down, wakes from sleep	its analog input is ADC2, which the radio blocks — digital only here
6	6	✅ good	input, output, pull-up, pull-down
7	7	✅ good	input, output, pull-up, pull-down
10	10	✅ good	input, output, pull-up, pull-down
20	20	✅ good	input, output, pull-up, pull-down	UART0 RX — unused here (the console runs on USB)
8	8	⚠️ caution	output	STRAPPING + the onboard blue LED (on = LOW; a WS2812 pixel on the Plus). Outputs only; anything holding it low at reset blocks flashing
9	9	⚠️ caution	input, pull-up, pull-down	STRAPPING + the BOOT button: low at reset = download mode. A button here is fine (don’t hold it while resetting); inputs only
21	21	⚠️ caution	input, output, pull-up, pull-down	UART0 TX: the boot ROM prints here at power-up — fine for a light or strip, not for a relay or motor. The console uses USB, not this pin
18	18	⛔ reserved		USB D− — the console and the flasher live on the USB port
19	19	⛔ reserved		USB D+ — the console and the flasher live on the USB port