H4x0ring Price Chopper

Forewarning: I may or may not have participated in any of the events listed herein. This may be pure fiction, take from it what you will. That said, it was pretty awsome…

If you’ve ever been to a supermarket in a city (like Worcester), you’ll have likely noticed a locking mechanism on one of the front wheels. It’s designed to lock the cart so that it won’t roll when you try to take it off the lot, so that people don’t steal them.

Around the perimeter of the parking lot, there is a wire acting as an antenna, transmitting an 8 khz square wave gated at 30 ms. This is the locking function. Using two LM555 timers, a few capacitors and resistors, and a coil of wire, a friend and I made our own transmitter.

The transmitter was in my pocket with two switches: to select between lock and unlock, and to active the coil. Since the coil was down at my ancle, this waranted a wire up my pants.





We headed down to the supermarket in the middle of the night, and walked past a line of carts outside: click click click click click click click. They were all locked. The transmitter worked the first time.

We went inside and locked a few carts while they were moving as well, which obivously confused the people moving them.

If you’ve ever been to a supermarket in a city, you’ll have likely seen a lock on one of the front wheels of the carts to prevent people from stealing them. A friend and I managed to make a transmitter so that we could the carts would lock when I walked by with the transmitter in my pants.