Hacking Bluetooth Sports Tech for Fun and Profit — Part 4: Understanding the WHOOP Protocol With a £12 Sniffer

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 advertises standard BLE services — Heart Rate (0x180D), Battery (0x180F), Device Information (0x180A) — but they&apos;