How a Raspberry Pi, two Nordic dongles, and a carefully-timed Bluetooth toggle revealed an undocumented protocol variant. The WHOOP is a fascinating device to reverse-engineer because it almost looks open. It

After a chest strap that leaked its ECG by accident and a band that hid everything behind one undocumented byte, here's the device that comes with a manual, and what I

Reverse-engineering the Wahoo TRACKR HR — no documentation, no SDK, no authentication. Just a BLE connection and methodical curiosity. The Wahoo TRACKR HR is a rechargeable chest strap heart rate monitor. It costs

How much data is your heart rate monitor actually capable of sharing, and what else could you use? If you've ever worn a Bluetooth chest strap during a run or a