Eric Nam Demonstrates OpenHaystack's ESP32-Powered AirTag Compatibles — But Raises Privacy Warnings

Despite using only Bluetooth Low Energy, the ESP32Tag offers accurate location tracking to within 10 feet — and that can be a problem.

Electronics YouTuber Eric Nam, also known as "That Project," has shown off just how accurate Apple's AirTag tracking system can be — even when you've created your own AirTag-compatible trackers using an Espressif ESP32 microcontroller and the OpenHaystack project — but warns of privacy issues yet to be resolved.

"You can leverage the OpenHaystack project to make the ESP32 work similar to AirTag's BLE [Bluetooth Low Energy] feature," Nam explains. "It can act as an Apple accessory and obtain location information through Apple's server."

ESP32-based AirTag-like devices can track with surprising accuracy, despite being limited to BLE. (📹: That Project)

Nam built his first AirTag-compatible, dubbed the ESP32Tag, earlier this year, using the open source OpenHaystack project to apply a firmware to the low-cost Bluetooth Low Energy-capable microcontroller in order to add compatibility with the Find My ecosystem, which powers Apple's object trackers.

Building another ESP32Tag using a WEMOS LOLIN32 Lite board, Nam set about demonstrating its capabilities by tracking his wife's car — with her permission, of course. "I will compare the location through the GPS installed in the vehicle," Nam explains. "Since this is GPS information, it's showing the vehicle's location very accurately. Also, because it's parked outdoors, the accuracy is very high.

"Comparing the two locations there seems to be a difference of about three meters [ten feet], I guess. This is a very satisfactory level. Honestly, I'm very happy with this result. Being able to access Apple's Find My network through this OpenHaystack is like a dream come true. Their magic key acquisition through reverse-engineering is amazing."

There's a darker side to the experiment, however: What if Nam hadn't sought his wife's permission to be tracked? "Since Apple does not officially support this," he admits, "there is no protection whatsoever. This can lead to more serious privacy issues. We should think about how we can solve this problem."

Nam's full video is available on the That Project YouTube channel, while OpenHaystack is published by the Secure Mobile Networking Lab on GitHub under the reciprocal GNU Affero General Public License 3.

Nam has also revealed a work-in-progress effort to add Ultra-Wideband (UWB) to OpenHaystack to more closely mimic the functionality of a real Apple AirTag, using Bluetooth Low Energy for general positioning and UWB for short-range homing, but has not indicated a timescale for release.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire:
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