Consumer B Gone enables you to block a shopping cart by just playing some tones out of your mobile phone speaker as a song or as a ringtone. Consumer B Gone is born from the incredible shock that the shopping cart wheel could be remotely locked if you tried to exit the supermarket parking lot.
The root cause of it was an antenna (a wire in the ground at the exit of the parking lot) which sent a “Lock” signal to 2 of the 4 shopping cart wheels.
If an antenna can do it, I can do it too! The first idea that emerged was to create some hardware to generate such signal… but the hardware didn’t work, so the logic was to test the generated signal against the original signal… and to use a soundcard to record both!
Well… if one soundcard can record, maybe it could be used also to replay??? Replay of course in the adequate coil that serves as an antenna… But hey, wait! What if the coil to be used was the one in the computer’s speaker? Guess what: IT WORKS.
And what about an MP3 File on mobile phones? Guess what again, IT WORKS TOO!!!
Consumer B Gone is indeed viral (send it through MMS or Bluetooth, share it with friends), is a great tool for the “no shopping day” and an excellent illustration of security systems that go wrong!
Of course, it’s not the sound that blocks the wheel but the electromagnetic parasites that are produced by the coil in any speaker. Just play the tone, put your mobile phone against the wheel and here you go, “Yuppie John’s shopping cart doesn’t roll very well anymore!”.
This is an interesting use of a side effect (the electromagnetic parasite of the phone speaker) used to create the adequate radio signal.
There’s even a way, thanks to your mobile phone’s jack or computer plug, to make it work better, from remote, without any noise.
One can also use his mobile phone to unlock carts in the same way.