Colonel Panic's OUI-SPY Is a Slick Bluetooth Low Energy Scanner — Or a "Foxhunting" Handset

Pseudonymous maker and punster "Colonel Panic" has designed a Bluetooth Low Energy gadget for tracking devices, either as a detector or for use as a direction-finder in "foxhunting" games: the OUI-SPY.

"OUI-SPY [is an Espressif] ESP32-S3 based BLE detection system with integrated buzzer and power management," Panic explains of the project. "This board has some artistic PCB art. Ready-to-use, no additional components required. Multi-target BLE device scanner with OUI filtering [or] precision proximity tracker for radio direction finding."

The two-board OUI-SPY, the silkscreen layer of which is decorated with a quote from the 1995 classic Hackers — "snoop unto them as they snoop unto us" — is powered by a Seeed Studio XIAO ESP32S3 and its Espressif ESP32-S3 processor, giving it a dual-core Tensilica Xtensa LX7 microcontroller and integrated Bluetooth Low Energy (BLE) and Wi-Fi connectivity.

The former is used to drive the OUI-SPY's two modes. The first acts as a multi-target BLE device scanner, capable of tracking and filtering by MAC address or Organizationally Unique Identifiers — meaning it can track by manufacturer as well as by individual device. In this mode, the Wi-Fi radio is used to provide a browser-based interface for easy configuration and an on-board buzzer provides audible alerts.

The second mode is rather more fun: Foxhunter. In this mode, the OUI-SPY locks on to a single device and tracks its signal strength, mapped to variable-speed beeping on the buzzer. This, its creator explains, means it can be used in "foxhunting" competitions to track a BLE-enabled target device — or for asset tracking.

Panic has published binary firmware for both options on GitHub, while fully-assembled units can be purchased on Tindie at $75 each; if you'd prefer to assemble your own OUI-SPY, bare PCBs are available at $20 the pair.