What is an ESP32?

Beginner | 6 min read

An ESP32 is a small, cheap computer chip made by a company called Espressif. Like an Arduino, it runs one program you write and controls lights, motors and sensors. The big difference: it has Wi-Fi and Bluetooth built in. That means your project can send data to your phone or the internet without any extra parts.

ESP32 or Arduino Uno?

Words explained: MHz is how many million steps a chip does per second. More MHz means faster. Pin voltage is the voltage a pin uses for “on”.

The one thing to remember: 3.3 volts

ESP32 pins work at 3.3V. Many beginner sensors, like the HC-SR04 ultrasonic sensor, send back 5V. Feeding 5V into an ESP32 pin can damage it. The fix is simple: a level shifter, or two resistors as a voltage divider (1 kΩ and 2 kΩ) on the sensor's output wire.

What can you build?

• A weather station that shows temperature and humidity on your phone (ESP32 + DHT22)
• Switching a lamp from anywhere using a relay
• A long-range sensor network with a LoRa module

Your first program

Install the free Arduino IDE, add the ESP32 boards package, choose “ESP32 Dev Module”, and upload this blink sketch:

void setup() { pinMode(2, OUTPUT); }
void loop() {
  digitalWrite(2, HIGH); delay(500);
  digitalWrite(2, LOW);  delay(500);
}

The small blue LED on the board starts blinking. Beep! You're programming an ESP32.