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Warshopping: Phreaking Smart Shopping Cart Wheels Through RF Sniffing

Joseph Gabay

Reverse engineers electronic shopping cart containment wheels, capturing ultra-low-frequency and 2.4 GHz RF signals to unlock wheel braking mechanisms.

Summary

Containment Systems in Smart Shopping Carts

Retailers deploy electronic cart wheels with integrated mechanical brakes to prevent cart theft, triggering locking mechanisms via subterranean low-frequency perimeter coils.

Sniffing Ultra-Low-Frequency and 2.4 GHz Signals

Joseph Gabay analyzes the Rocateq smart wheel system, capturing perimeter boundary signals and 2.4 GHz register checkout broadcasts using software-defined radio.

Hardware Teardown and Firmware Extraction

Soldering test leads onto the wheel's internal PCB enables logic analyzer tracing of chip-to-chip serial buses, while a PICkit programmer dumps firmware for Ghidra analysis.

Simulating Control Codes via Audio Transducers

Because the wheel coils respond to low-frequency magnetic modulation, Gabay demonstrates triggering and disarming cart wheel locks directly from a smartphone speaker.

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