The ESP32-C3 Super Mini is a compact yet highly capable development board based on the ESP32-C3 microcontroller. Designed for IoT applications, smart devices, and low-power wireless projects, it delivers impressive performance with cutting-edge connectivity. Whether you’re an experienced engineer or an enthusiastic maker, the ESP32-C3 Super Mini offers a reliable and accessible path to rapid innovation. In this guide, you’ll learn everything about the ESP32-C3 Super Mini pinout — clearly and comprehensively.
What is the ESP32-C3 Super Mini?
System-on-Chip (SoC):
At the core of the ESP32-C3 Super Mini lies the ESP32-C3 SoC from Espressif Systems — a single-core 32-bit RISC-V processor running up to 160 MHz. It integrates Wi-Fi (802.11 b/g/n) and Bluetooth 5 (LE) in a highly efficient package.
Development Board:
The ESP32-C3 Super Mini is a minimalist development board based on the ESP32-C3 chip. It integrates the SoC, flash memory (typically 4MB), a crystal oscillator, passive components, a USB-to-Serial bridge, and basic voltage regulation into an ultra-compact PCB. This small yet powerful board provides direct USB programming and nearly full GPIO breakout, making it perfect for space-constrained and low-power wireless applications.
Designed for Wireless Innovation and Low Power
The ESP32-C3 Super Mini offers a remarkable range of features for wireless and embedded projects:
- Wi-Fi 4 (802.11 b/g/n, 2.4 GHz)
- Bluetooth 5 (LE)
- 22 programmable GPIOs
- 12-bit ADCs
- PWM outputs on all GPIOs
- SPI, I2C, UART, I2S, LEDC, RMT
- Hardware Cryptographic Acceleration (AES, SHA-2, RSA, ECC, HMAC)
- Deep Sleep & ULP (Ultra-Low Power Co-Processor)
With these capabilities, the ESP32-C3 Super Mini is ideal for secure IoT devices, wireless sensors, and portable smart gadgets.
** ESP32-C3 Super Mini Pinout is available for download at the end of this post in high resolution – for free!
ESP32-C3 Super Mini – GPIO Fundamentals
The ESP32-C3 Super Mini exposes nearly all the ESP32-C3’s GPIOs. However, like every ESP chip, not all pins are created equal. Let’s dive deeper:
Input-Only Pins
- GPIO2, GPIO8, GPIO9
These pins are input-only and cannot drive external outputs. They are ideal for reading buttons or sensors but unsuitable for actuating devices.
Special Function Pins
SPI Flash Connected Pins
- GPIO7, GPIO8, GPIO9, GPIO10, GPIO11
These pins connect internally to the board’s SPI flash memory and should not be reassigned in most cases. Misusing them can lead to boot failures or crashes.
Pro Tip:
GPIO8 and GPIO9 are input-only because of this flash connection.
Advanced GPIO Features
ADC (Analog-to-Digital Converter)
The ESP32-C3 features a 12-bit ADC available on multiple pins:
- ADC1 Channels: GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO6
Applications:
Temperature monitoring, light sensors, battery voltage monitoring.
PWM (Pulse Width Modulation)
Every GPIO (except input-only pins) supports PWM using the LEDC peripheral.
Applications:
LED brightness control, motor speed control, audio signal generation.
I2C Communication
The ESP32-C3 supports two I2C controllers. You can configure any available GPIO for I2C, but defaults often used:
- SDA: GPIO8
- SCL: GPIO9
Applications:
Connect OLED displays, environmental sensors, real-time clocks.
SPI Communication
SPI peripherals allow the board to communicate with high-speed devices like displays, memory cards, or specialized chips.
Common SPI Pins (for VSPI):
- MOSI: GPIO6
- MISO: GPIO5
- SCLK: GPIO4
- CS: GPIO7
Caution: Avoid reassigning GPIO7 for SPI unless you are not using flash memory externally.
UART Communication
The ESP32-C3 Super Mini offers UART for serial communication.
Default UART0 pins for programming and console:
- TXD: GPIO21
- RXD: GPIO20
Additional UARTs can be mapped freely onto other available GPIOs.
RTC GPIO’s (Real-Time Clock GPIOs)
The ESP32-C3 has low-power GPIOs to interact even during deep sleep:
- RTC-enabled Pins: GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO6, GPIO7, GPIO8, GPIO9, GPIO10, GPIO11, GPIO12, GPIO13, GPIO18, GPIO19, GPIO20, GPIO21
Applications:
Wake up from deep sleep on external events (button press, sensor trigger).
ESP32-C3 Super Mini GPIO Quick Reference Table
| GPIO | Special Function | ADC | PWM | RTC | Boot Function |
|---|---|---|---|---|---|
| 0 | Strapping | ADC1_CH0 | Yes | Yes | Low (Boot select) |
| 1 | UART0 TXD | ADC1_CH1 | Yes | Yes | Free |
| 2 | Input-only | ADC1_CH2 | No | Yes | Free |
| 3 | UART0 RXD | ADC1_CH3 | Yes | Yes | Free |
| 4 | SPI CLK | ADC1_CH4 | Yes | Yes | Free |
| 5 | SPI MISO | ADC1_CH5 | Yes | Yes | Free |
| 6 | SPI MOSI | ADC1_CH6 | Yes | Yes | Free |
| 7 | SPI CS | None | Yes | Yes | Connected to Flash |
| 8 | Input-only (I2C SDA) | None | No | Yes | Connected to Flash |
| 9 | Input-only (I2C SCL) | None | No | Yes | Connected to Flash |
| 10 | SPI | None | Yes | Yes | Connected to Flash |
| 11 | SPI | None | Yes | Yes | Connected to Flash |
| 18 | UART1 RX | None | Yes | Yes | Free |
| 19 | UART1 TX | None | Yes | Yes | Free |
| 20 | UART0 RXD | None | Yes | Yes | Free |
| 21 | UART0 TXD | None | Yes | Yes | Free |
Best Practices and Common Mistakes
- Mind the Strapping Pins:
GPIO0 is a strapping pin. It affects boot mode (flashing or normal boot). Do not pull it high during boot if flashing. - Avoid Overloading Input-only Pins:
GPIO2, GPIO8, and GPIO9 cannot drive outputs. - Care with Flash SPI Pins:
Do not use GPIO7-11 unless you really know what you are doing. - Use Pull-ups Where Needed:
For buttons or open-drain outputs. - Respect GPIO Current Limits:
Each GPIO should not exceed ~12mA output drive strength for reliable operation. - Debounce your Buttons:
Mechanical bouncing can create false triggers without software or hardware debouncing.
How to Program the ESP32-C3 Super Mini
Development Environments:
- Arduino IDE (with ESP32-C3 core installed)
- PlatformIO (powerful and scalable)
- ESP-IDF (official Espressif SDK)
Programming Pins:
| Function | Pin | Description |
|---|---|---|
| TXD0 | GPIO21 | ESP32 to PC (TX output) |
| RXD0 | GPIO20 | PC to ESP32 (RX input) |
| EN | EN pin | Resets the ESP32 |
| IO0 | GPIO0 | Puts ESP32 into flashing mode |
Programming Steps:
- Connect via USB-C.
- Install necessary drivers (if required: CH340, CP210x, etc.).
- Select board type: ESP32C3 Dev Module (Arduino) or configure in PlatformIO.
- Upload your code.
Tip: Most boards support auto-reset. If upload fails, press and hold BOOT during upload.
Conclusion: Compact, Capable, and Connected
The ESP32-C3 Super Mini redefines what’s possible in small form factor embedded systems. Combining secure wireless connectivity, low power features, and powerful peripherals, it opens endless opportunities for makers and professionals alike. Mastering its pinout is the first step toward building the next generation of smart, connected products.
Happy Innovating!
👉 Download the ESP32-C3 Super Mini Pinout Diagram here – Free!
(Licensed under MIT — Attribution appreciated!)