Getting started with the ESP32: your first Wi-Fi project

The ESP32 packs a dual-core processor, Wi-Fi and Bluetooth into a board that costs less than a pizza. In this guide you will install board support in the Arduino IDE, upload a blink sketch and then serve a tiny web page that switches an LED from your phone. First, open File > Preferences and add the Espressif board manager URL. Install the esp32 package from the Boards Manager, choose "ESP32 Dev Module" and select the right COM port. Upload the Blink example to confirm everything works. Next, open WiFi > SimpleWiFiServer, enter your network name and password, and upload. Open the Serial Monitor to find the board's IP address, visit it in a browser, and you are controlling hardware over Wi-Fi. From here you can add a DHT22 for temperature, a relay module for appliances, or an OLED to show status. Keep mains wiring to qualified people and always use opto-isolated relays.