ESP32

Work with IoT on the ESP32's built-in Wi-Fi/Bluetooth. Web servers, BLE, MQTT cloud integration, deep-sleep power management, OTA updates — read real code, diagnose communication bugs, and review AI-proposed changes.

Projects

1. Build a Wi-Fi web server

   ~100 minSign in & start

   Make an ESP32 serve web pages itself using WiFi.h and the WebServer library. Read real routing code, all the way to toggling an LED from a button in the browser.

2. Talk to a phone over BLE

   ~110 minSign in & start

   Implement Bluetooth Low Energy communication with a phone app using BLEServer/BLECharacteristic. See GATT service/characteristic concepts in real code, and diagnose the common bug of dropped connections.

3. Push sensor data to the cloud with MQTT

   ~120 minSign in & start

   Publish and subscribe sensor data to an MQTT broker with PubSubClient. Work with reconnection logic and QoS, the common patterns of real IoT communication.

4. Save battery with deep sleep

   ~100 minSign in & start

   Minimize power draw on a battery-powered IoT sensor with esp_sleep_enable_timer_wakeup. See in real code how RTC memory keeps values alive across deep sleep cycles.

5. Update firmware over the air with OTA

   ~120 minSign in & start

   Upload new firmware over Wi-Fi with ArduinoOTA, no USB cable needed. The wrap-up lesson that combines everything built so far — Wi-Fi, BLE, MQTT, deep sleep — into one IoT device project.