# 📶 ESP32 BLE Gadget: Build a Two-Way Phone Device

A fast, hands-on path from unboxing an ESP32 dev board to a working two-way BLE gadget. Set up PlatformIO in VS Code, flash working sketches, expose a custom GATT service that streams sensor data to a phone and accepts control commands, then test, harden, and demo the finished device.

## Contents

- [🔌 Meet the ESP32 Dev Board](/courses/esp32-ble-gadget-build-a-two-way-phone-device/esp32-dev-board-tour.md)
- [🛠️ Install PlatformIO and Flash a Blink Sketch](/courses/esp32-ble-gadget-build-a-two-way-phone-device/platformio-first-upload.md) (sign-in required)
- [🖨️ Read Serial Output and Debug the Board](/courses/esp32-ble-gadget-build-a-two-way-phone-device/serial-monitor-debugging.md)
- [✅ Checkpoint: ESP32 and Toolchain Basics](/courses/esp32-ble-gadget-build-a-two-way-phone-device/checkpoint-esp32-toolchain-basics.md)
- [📶 BLE Basics and Designing Your Gadget's GATT Service](/courses/esp32-ble-gadget-build-a-two-way-phone-device/ble-gatt-service-design.md)
- [📡 Stream Sensor Data to the Phone with BLE Notifications](/courses/esp32-ble-gadget-build-a-two-way-phone-device/ble-notify-sensor-data.md)
- [🎛️ Receive Control Commands from the Phone](/courses/esp32-ble-gadget-build-a-two-way-phone-device/ble-receive-control-commands.md)
- [✅ Checkpoint: BLE Two-Way Communication](/courses/esp32-ble-gadget-build-a-two-way-phone-device/checkpoint-ble-two-way.md)
- [📱 Test Your Gadget with a Phone App](/courses/esp32-ble-gadget-build-a-two-way-phone-device/phone-testing-nrf-connect.md)
- [🧯 Handle Disconnects and Common BLE Pitfalls](/courses/esp32-ble-gadget-build-a-two-way-phone-device/ble-reconnect-troubleshooting.md)
- [🏁 Capstone: Finish and Demo Your BLE Gadget](/courses/esp32-ble-gadget-build-a-two-way-phone-device/capstone-ble-gadget-demo.md) (paid)
- [✅ Checkpoint: Gadget Reliability and Shipping](/courses/esp32-ble-gadget-build-a-two-way-phone-device/checkpoint-gadget-shipping.md) (paid)
- [Course cheatsheet](/courses/esp32-ble-gadget-build-a-two-way-phone-device/cheatsheet.md) (paid)