Espressif ESP32-C3
ESP32-C3 Super Mini Pinout
The ESP32-C3 Super Mini packs Wi-Fi 4 and Bluetooth 5 (LE) into a postage-stamp footprint with a USB-C port and 11 broken-out GPIOs. It runs a single-core 160 MHz RISC-V CPU and is the cheapest way to add wireless to a project.
Specifications
- MCU
- ESP32-C3FN4 (RISC-V single-core, 160 MHz)
- Flash
- 4 MB
- SRAM
- 400 KB
- GPIO
- 11 broken out (of 22 total)
- ADC
- 5 channels, 12-bit
- Operating voltage
- 3.3V (USB-C provides 5V input)
Pin reference
| Pin | Name | Type / functions | Notes |
|---|---|---|---|
| 5V | 5V | Power | USB-C VBUS, also usable as input. |
| GND | Ground | Power | — |
| 3V3 | 3.3V | Power output | From onboard regulator, ~500 mA. |
| GPIO0 | GPIO0 | Digital I/O, ADC1_0 | — |
| GPIO1 | GPIO1 | Digital I/O, ADC1_1 | — |
| GPIO2 | GPIO2 | Digital I/O, ADC1_2 | Strapping pin — must be HIGH at boot. |
| GPIO3 | GPIO3 | Digital I/O, ADC1_3 | — |
| GPIO4 | MISO | Digital I/O, ADC1_4, SPI MISO | — |
| GPIO5 | MOSI | Digital I/O, SPI MOSI | — |
| GPIO6 | SCK | Digital I/O, SPI SCK | — |
| GPIO7 | SS | Digital I/O, SPI SS | — |
| GPIO8 | SDA / LED | Digital I/O, I2C SDA, onboard LED (active LOW) | Strapping pin — must be HIGH at boot. |
| GPIO9 | SCL / BOOT | Digital I/O, I2C SCL | Boot button — pull LOW at boot to enter download mode. |
| GPIO10 | GPIO10 | Digital I/O | — |
| GPIO20 | RX | Digital I/O, UART0 RX | — |
| GPIO21 | TX | Digital I/O, UART0 TX | — |
Gotchas
- 01Onboard LED on GPIO8 is active-LOW — digitalWrite(8, LOW) turns it on.
- 02GPIO2, 8, 9 are strapping pins. Holding them at the wrong level at boot blocks startup.
- 03Pin labels are tiny — double-check against the silkscreen before wiring.
- 04Some clones ship with USB CDC disabled in flash; if Serial doesn't appear, reflash with USB CDC On Boot enabled.
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