This Modded Shopping Cart Probably Isn’t Street Legal

July 18, 2024 by Bryan Cockfield 9 Comments

If you don’t count the high center of gravity, the weight limit, the weak chassis, or the small size, a standard shopping cart is an almost ideal platform for building a fun drifting kart. At least, that was [Garage Avenger]’s thought process when he started this build to turn a shopping cart into the ultimate drift vehicle.

The first thing on the list was to solve the issues with the high center of gravity and the fact that he couldn’t fit in the cart easily. Chopping out the back of the basket as well as everything beneath it solved both of these problems. From there a custom chassis could be fabricated from square steel tubing which includes a lever system which controls the rake of the caster wheels and thus their driftability. The power train and battery system for this build comes from a 2400 W electric scooter with a few modifications made to get it to fit on the new chassis.

After a test drive of the original prototype, a few modifications were made including using smaller caster wheels in the back, the addition of a spring to make the lever action for the rear wheels easier to engage, some front casters for stability, and a seat a little more substantial than the metal mesh of the cart. With all the electronics put into the cart, he’s ready to drift off into the sunset. This isn’t his first crazy vehicle, either. When winter rolls around you’ll find him getting around in a jet-powered sled instead.

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Shopping Cart Does The Tedious Work For You

December 29, 2022 by Bryan Cockfield 36 Comments

Thanks to modern microcontrollers, basic home automation tasks such as turning lights on and off, opening blinds, and various other simple tasks have become common DIY projects. But with the advent of artificial intelligence and machine learning the amount of tasks that can be offloaded to computers has skyrocketed. This shopping cart that automates away the checkout lines at grocery stores certainly fits into this category.

The project was inspired by the cashierless Amazon stores where customers simply walk into a store, grab what they want, and leave. This is made possible by the fact that computers monitor their purchases and charge them automatically, but creator [kutluhan_aktar] wanted to explore a way of doing this without a fleet of sensors and cameras all over a store. By mounting the hardware to a shopping cart instead, the sensors travel with the shopper and monitor what’s placed in the cart instead of what’s taken from a shelf. It’s built around the OpenMV Cam H7, a microcontroller paired with a camera specifically designed for these types of tasks, and the custom circuitry inside the case also includes WiFi connectivity to make sure the shopping cart can report its findings properly.

[kutluhan_aktar] also built the entire software stack from the ground up and trained the model on a set of common products as a proof-of-concept. The idea was to allow smaller stores to operate more efficiently without needing a full suite of Amazon hardware and software backing it up, and this prototype seems to work pretty well to that end. If you want to develop a machine vision project on your own with more common hardware, take a look at this project which uses the Raspberry Pi instead.

Shopping Trolley Is Wired For Camp

December 17, 2013 by Adam Fabio 13 Comments

[James] needed some cool transportation for the upcoming Easter Camp in New Zealand, so he created a custom motorized shopping trolley that is sure to turn heads. The base of this project is a standard mobility scooter, which conveniently has a modular design. All of the electronics have connectors for quick service and the entire rear axle and motor assembly pop off with the pull of a lever.

[James] had to do a bit of welding and chassis rework to achieve his goal of mounting a shopping cart top to the scooter’s frame. Once finished, though, the setup looked great. It was actually comfortable to sit in, as [James] made a cutout for the driver’s feet to pass through. The real fun came with the electronics. The trolley is the most wired mobility scooter mod we’ve ever seen. Most of the electronics are contained in a project box under the seat, with several Arduinos that control the various systems: interfacing with the original scooter electronics, a GPS receiver, and a GSM radio. [James] also went as far as to add RGB LED headlights, a horn, and a multi-tone siren from Jaycar.

Driving the trolley is simple. An arcade joystick selects the speed, and the scooter’s standard hand controls are used for forward, reverse, and steering. One of the more interesting mods [James] made was a custom Windows app to control the trolley via a USB radio module. The entire system can be secured, with the security code stored in NVRAM to prevent a power cycle from unlocking the system. [James] can even command the trolley to go forward or reverse from his touch screen. We’d love to see him add a steering servo to make it a completely remote-controlled solution, though this step would require some sort of clutch for manual control.

The final design works very well. [James] may not win any drag races by keeping scooter’s original speed controls and associated electronics, but he did extend the range with larger batteries, so we’re sure the trolley will be a hit all over the camp. Similar projects have been built using the base of an electric wheelchair. If you have one that you want to control without invasive changes to the hardware, check out this accessibility hack which interfaces using a connector.

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Reverse Engineering Shopping Cart Security

February 28, 2011 by Mike Szczys 30 Comments

All this talk about 555 timers is causing projects to pop out of the woodwork like this one that reverse engineers a shopping cart security mechanism. The wheel seen above listens for a particular magnetic signal and when encountered it locks down the yellow cowl, preventing the wheel from touching the ground and making the cart very hard to move.

[Nolan Blender] acquired one of these wheels for testing purposes and he’s posted some details about the hardware inside. But the first thing he did was to put together some test equipment to help find out details about the signal that trips the mechanism. He connected a coil to an audio amplifier and walked around the market looking for strong signals. Once he found a few strong bursts with that equipment he grabbed an oscilloscope, hooked it to the coil, and made some measurements. He found an 8 kHz signal at a 50% duty cycle at 30 ms intervals (it would be hard to make a better case for why you need an oscilloscope).

With the specs in hand, [Nolan] grabbed two 555 timers, an audio amplifier, and a 200 turn antenna around a ferrite core to build his own locking mechanism. If you’re ever stopped short in the middle of the market, just look for the hacker at the end of the aisle holding the homemade electronics.

[Photo source]

[Thanks Colin]