This is a fun project that walks through how to reverse engineer a smart light bulb that uses Bluetooth Low Energy (BLE) to change its color. I stumbled on the Smart Bulb Colorific! bulb recently at a local store and was intrigued by its Bluetooth-based control and relatively low price (for a 'smart' gadget at least). Because the light bulb uses Bluetooth Low Energy (which is a subset of Bluetooth 4.0) it means any BLE device can in theory control the bulb. But to control the bulb the protocol for communicating with it must be understood, and this guide will show you how to use the Bluefruit LE sniffer and other tools to reverse engineer a Bluetooth Low Energy gadget.
If you'd like to follow along and control a bulb yourself you'll first need a few things:
A Smart Bulb Colorific! light bulb. It's possible other BLE light bulbs can be controlled in a similar manner as discovered here, but I recommend picking up one of these bulbs to be sure you can control it. The bulbs use the Colorific! app on the Android or iOS app store for control. You can see a picture of the bulb I used to the left.
- Bluetooth 4.0 USB module. Make sure the module supports Bluetooth Low Energy. Older Bluetooth before version 4.0 does not support BLE!
- Raspberry Pi of any model (A, B, A+, B+, Pi 2, etc.). This guide shows how to use tools and code on the Pi to control the bulb. Another linux computer can be used but we've only tested it on the Pi
- Bluefruit LE Sniffer. The Bluefruit LE sniffer is a special version of the Bluefruit LE friend but with a firmware that allows it to watch BLE packets being sent to and from a device.
You should also familiarize yourself with Bluetooth Low Energy by first reading this introductory guide. This will help you understand terminology like GATT, service, and characteristic.
Continue on to learn where to start when exploring a Bluetooth Low Energy device.