ESP32 DevKit V1 Reference
A dual-core WiFi/Bluetooth-capable microcontroller board. Unlike the AVR-based Arduino
boards, all GPIOs run at 3.3V logic — do not drive them from 5V sources.
Pin names
| Pin ID | Label | Signal | Notes |
|---|
EN | EN | — | Enable / reset |
VP | VP (A0) | Analog | Input-only, ADC1 |
VN | VN (A1) | Analog | Input-only, ADC1 |
D34 / D35 | D34, D35 | Analog | Input-only pins |
D32 / D33 | D32, D33 | PWM | |
D25 / D26 / D27 | D25, D26, D27 | PWM | |
D14 / D12 / D13 | D14, D12, D13 | PWM | |
GND.2 | GND | Power | Ground |
VIN | VIN | Power | 5V input (via onboard regulator) |
| Pin ID | Label | Signal | Notes |
|---|
D23 | D23 | Digital | |
D22 | D22 / SCL | I²C | I²C clock |
TX0 / RX0 | TX0, RX0 | USART | Serial 0 (shared with USB) |
D21 | D21 / SDA | I²C | I²C data |
D19 / D18 / D5 | D19, D18, D5 | PWM | |
TX2 / RX2 | TX2, RX2 | USART | Serial 2 |
D4 / D2 / D15 | D4, D2, D15 | PWM | |
GND.1 | GND | Power | Ground |
3V3 | 3.3V | Power | 3.3 V output |
Quick reference
| Capability | Pins |
|---|
| Digital I/O | ~25 usable GPIOs |
| Analog input | VP/VN, D32–D35 (ADC1, input-only pins recommended when WiFi is active) |
| PWM output | Any GPIO via the LEDC peripheral (software-driven, not a fixed set of pins) |
| I²C | D21 (SDA), D22 (SCL) — remappable in software |
| USART | Serial 0 (TX0/RX0), Serial 2 (TX2/RX2) |
| Operating voltage | 3.3 V logic (VIN accepts 5V through onboard regulator) |
| Clock speed | 240 MHz dual-core |
| Wireless | WiFi (802.11 b/g/n), Bluetooth Classic + BLE |
Usage
#include <WiFi.h>
void setup() {
pinMode(2, OUTPUT);
Serial.begin(115200);
WiFi.begin("your-ssid", "your-password");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\nConnected: " + WiFi.localIP().toString());
}
void loop() {
digitalWrite(2, HIGH);
delay(500);
digitalWrite(2, LOW);
delay(500);
}
All GPIOs are 3.3V — connecting a 5V signal directly (e.g. from a 5V sensor's output) can
damage the board. Use a logic-level shifter or voltage divider for 5V peripherals.
See also