NodeMCU-ESP32-C2 Pinout

The NodeMCU-ESP32-C2 is a NodeMCU-style development board built around Espressif’s ESP8684-WROOM-02 module, a different, larger module than the bare ESPC2-02 module this site already documents. Same ESP32-C2 chip underneath, more pins broken out and a full USB-C/CH340C programming circuit on board. This guide covers this specific development board: its GPIO layout, communication pins, and how to flash it.

System-on-chip and module

At the heart of this board is the ESP32-C2, marketed name for the ESP8684 chip: a single-core RISC-V SoC from Espressif with integrated 2.4GHz Wi-Fi, a secure bootloader and hardware encryption, built for low-cost, low-resource applications.

The board carries the ESP8684-WROOM-02 module: the chip, 2MB of SPI flash, a PCB antenna and the surrounding passives in one shielded package.

The development board itself breaks the module’s pins out to a breadboard-friendly, clearly labeled NodeMCU-style header, adds a CH340C USB-to-serial chip, and uses USB-C instead of micro-USB.

Key features

• Wi-Fi 802.11 b/g/n (2.4GHz)
• 12-bit ADC on 5 of the exposed pins
• UART, SPI, I²C and PWM, all software-assignable
• USB-to-serial via onboard CH340C, no separate programmer needed
• USB-C connector
• 2MB flash, embedded in the module

This is a smaller, cheaper board than the ESP32-S3/-C3/-C6 family: fine for simple sensors, wireless switches and other low-power, low-complexity connected devices, not for anything CPU- or memory-heavy.

GPIO quick reference

All GPIOs are bidirectional digital I/O and support PWM. Remap I²C in Arduino with Wire.begin(SDA, SCL).

Flashing

Thanks to the onboard CH340C, flashing is plug-and-play over USB-C, no external USB-to-serial adapter needed.

1. Connect the board via USB-C.
2. In Arduino IDE or PlatformIO, select a generic ESP32C2 Dev Module board.
3. Click Upload.
4. If flashing fails to start automatically, hold IO9 (BOOT) low, tap EN/RESET, release IO9, then retry.

Do not hold IO9 low outside of flashing, it forces the board back into the bootloader instead of running your program.

Conclusion

The NodeMCU-ESP32-C2 trades GPIO count and processing power for cost and simplicity. If a project genuinely only needs Wi-Fi plus a handful of digital/analog pins, this is a cheaper, lower-power alternative to reaching for an ESP-WROOM-32D or ESP32-C3 board. For anything needing more GPIOs, Bluetooth, or more RAM, look at this site’s other ESP32 boards instead.

Related

Reference ADS1115 16-Bit ADC A precision 16-bit I2C analog-to-digital converter for when the ESP32’s own noisy 12-bit ADC is not accurate enough. Covers single-ended and differential inputs, the programmable gain amplifier, and reading a signed conversion result correctly. Read more › Reference The Ultimate Guide to the BL0942 Energy Meter IC A calibration-free, register-driven single-phase energy metering IC: active power, RMS, line frequency and zero-crossing, all exposed over UART or SPI instead of pulse-counting alone. This guide covers its pinout, digital interfaces, and how it compares to the older BL0937. Read more › Guide ESP32-C2 (ESPC2-02) Pinout The complete pin reference for the ESPC2-02 module: Espressif’s smallest, lowest-cost Wi-Fi and Bluetooth chip, and the exact pins you can safely reuse. Read more ›