Summary
break into the system.
We previously covered the journey in getting the vending machine back into a state where it’d actually reliably produce cotton candy again, a process which is quite tedious and temperamental. After a lot of fiddling with sensors and temperature settings this was fixed, but still left the issue that as a vending machine it should allow the owner to set prices and such. Sadly this could only be done remotely via a special account, which access to had been left with the previous owner.
Despite the very custom exterior, the vending machine runs what is effectively an Android system, consisting of an industrial computer board wired into a lot of stepper drivers and other control boards. To the extreme delight of everyone involved, it was possible to access the Ct Terminal
application with adb
and its product database on the device’s storage. Unfortunately writing back a changed database file didn’t change anything in the UI, so for a few months the project languished.
After nearly bricking the system and ending up factory resetting the control software including temperatures, it actually improved the performance of the machine and produced cotton candy, so that was one win. Ultimately the solution was to modify the original app, but a combination of weak coding skills and the app being in Chinese led him to use free LLM coding chatbots to assist here.
This resulted in a custom settings menu being added with the ability to modify pricing, no need for online access any more and a very nice cotton candy vending machine for the private arcade where presumably friends and family can enjoy cheap or even free cotton candy. Finally having the machine sealed against ant intrusion was also a major improvement.
Back in 2002(?) my high school got one of those coke vending machines with the gantry and belt that dumped the bottle off to the side. My buddy and I spent countless hours trying to fine a way to hack the button pad interface looking for service codes to override the machine.
We eventually talked to a tech working on it. He knew what we were up to and told us the codes… only for us to find out you had to have access to the inside of the machine for them to work. But he gave us two nearly expired drinks for free so we called it win.
Memories of debugging MDB protocol still make me shiver.
Company I worked for did a project with one of the two big names in vending machines. I learned a lot. Believe me, if you thought of a way to hack the machine, they’ve already thought of it and fixed it. One of their engineers was visiting and told us stories. One of their female workers has very long skinny arms, and she’s the “can you reach in and grab it” tester. You know the “Do Not Tip Machine” stickers? Those things are wicked heavy, and they have found them on top of deceased people who were rocking the machine to try to get free stuff. There are sharp blades and catches to counter the “coin on a string” trick. All sorts of clever countermeasures. And when they find a machine that’s been beaten, they ship it back to the factory to figure out how it was done.
Yeah, it was a very fun project…came to nothing in the end because they tested consumer reaction to the product after development!? I could have had a machine for my garage, but the things weigh hundreds of pounds and I couldn’t justify dragging one home.
I remember a tecnician once left the joy stick panel loose on an arcade machine, and we kids discovered we could lift it up and reach down and toggle the credit lever racking up 100’s of credits. We would play for a couple of hours then turn around and sell the rest of the credits to the kid patiently waiting his turn. One day while reaching down, my finger hooked a ring. I pulled it up and there was the spare key to the rear panel. A day later the tecnician returned and closed the joystick panel but we had the keys. It was a longer reach from the rear of the machine but we could just manage to toggle the credit lever. This went on for weeks until we discovered the key also opened up the money box which we would dutifully empty all the quarters into our large coke cups. It was a lot of fun. Alas, we we’re little rascals!
I just saw this machine’s twin in Faneuil Hall (Quincy Market) in Boston last week. Pretty clever, but I wasn’t in the mood for colored cotton candy.