ESP32-C2 (ESPC2-02) Pinout

Overview

This guide covers the ESPC2-02 module, built around Espressif’s ESP32-C2 chip. The chip itself is manufactured and marked as ESP8684, ESP32-C2 is Espressif’s marketing name for the same silicon. It’s Espressif’s smallest and lowest-cost Wi-Fi chip, aimed at simple connected devices rather than complex projects, so this compact module only exposes a subset of the chip’s GPIOs.

No 802.15.4 radio on this chip, so Thread and Zigbee aren’t possible here. (Only badges for protocols this exact chip actually supports are shown, no Wi-Fi 6/7 either: this is 802.11 b/g/n.)

Getting started

This module is usually wired up directly rather than plugged into a ready-made development board, so the three steps below assume you have a USB-to-serial adapter (or a carrier board that includes one). See “Flashing pins” further down for exactly which pins that adapter needs.

Hello World: blink an LED

The microcontroller equivalent of “Hello World”: GPIO18 toggles once a second, shown here in two different environments. Wire an LED (with a resistor) to GPIO18, a plain general-purpose pin with no other job on this module.

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"

#define LED_PIN GPIO_NUM_18

void app_main(void)
{
    gpio_reset_pin(LED_PIN);
    gpio_set_direction(LED_PIN, GPIO_MODE_OUTPUT);

    while (1) {
        gpio_set_level(LED_PIN, 1);
        vTaskDelay(pdMS_TO_TICKS(1000));
        gpio_set_level(LED_PIN, 0);
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

#define LED_PIN 18

void setup() {
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_PIN, HIGH);
  delay(1000);
  digitalWrite(LED_PIN, LOW);
  delay(1000);
}

ESP-IDF: build and flash with idf.py build flash monitor. Arduino IDE: install ESP32 board support first, see “Getting started” above.

Specifications

Official Espressif specifications for the ESP32-C2 (ESP8684) chip.

Pinout diagram

The 12-pad layout of the ESPC2-02 module. This is a compact breakout, not every GPIO on the underlying chip is brought out to a pad.

GPIO quick reference

This chip only has ADC1, no ADC2, DAC or capacitive touch peripheral.

Flashing pins (UART0)

Used by a USB-to-serial adapter to upload firmware, this module has no onboard one.

Safety notes