vending machine

29 Articles

Hacking A $6000 Cotton Candy Machine To Fully Control It

August 7, 2026 by 7 Comments
Some of the cotton candy options by the machine. The Chinese text reads 'flower type'.
Some of the cotton candy options by the machine. The Chinese text reads ‘flower type’.

Having a fully automated cotton candy vending machine in your possession is a great thing, but not if you do not have full access to its software. With [Block’s Retro Repairs] getting ghosted by the manufacturer on regaining account access to the machine he bought used for $300, there was little left but to try and 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.

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A photo of the vending machine sitting on an electronics workbench

Building A Halloween Vending Computer That Talks

September 1, 2025 by 1 Comment

Our hacker from [Appalachian Forge Works] wrote in to let us know about their vending machine build: a Halloween vending computer that talks.

He starts by demonstrating the vending process: a backlit vend button is pressed, an animation plays on the screen as a synthetic voice speaks through attached speakers, the vending mechanism rotates until a successful vend is detected with a photoelectric sensor (a photoresistor and an LED) or a timeout of 10 seconds is reached (the timeout is particularly important for cases when the stock of prizes is fully depleted).

For a successful vend the prize will roll out a vending tube and through some ramps, visible via a perspex side panel, into the receptacle, as the spooky voice announces the vend. It’s the photoelectric sensor which triggers the mask to speak.

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You’ve Got Mail: Faster And Faster We Go

September 27, 2023 by 9 Comments

When we last left the post office, they had implemented OCR to read even the sloppiest of handwriting. And to augment today’s 99% accuracy rate, there’s a center full of humans who can decipher the rest of those messy addresses with speed and aplomb. Before that, we took a look at many of the machines that make up the automated side of the post office’s movements. But what was being done to improve the customer experience during all of this time?

Quite a bit, as it turns out. In this installment, we’ll take a look at the development of vending machines and programs like Speed Mail, Missile Mail, and V-Mail (no, not voicemail!) as they relate to enhanced customer service over the years.

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I’m Your Overlord, May I Take Your Order?

August 18, 2022 by 44 Comments

If you’ve ever been at an eatery and thought the server was a bit robotic, you should try San Francisco’s Mezli. The restaurant claims to be the first one to be totally automated. There are no humans in there. The restaurant serves Mediterranean grain bowls. Honestly, it is hard to decide if Mezli is a restaurant or a very sophisticated vending machine.

Then again, that makes sense. Only in science fiction do you have androids flying spaceships. In real life, the robot probably is the spaceship. Obviously, someone is still loading ingredients into the machine — some precooked — but that’s about it. Some restaurants let you order from a computer while a human makes your food and we’ve seen a few automated chefs, but nothing with this degree of mechanization.

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Cracking The MiFare Classic Could Get You Free Snacks

July 13, 2022 by 24 Comments

[Guillermo] started a new job a while back. That job came with an NFC access card, which was used for booking rooms and building access. The card also served as a wallet for using the vending machines. He set about hacking the card to see what he could uncover.

Initial scans with NFC Tools revealed the card was an Infineon MIFARE Classic Card 1k. These cards are considered fairly old and insecure by now. There’s plenty of guides online on how to crack the private keys that are supposed to make the card secure. Conveniently, [Guillermo] had a reader/writer on hand for these very cards.

[Guillermo] was able to use a tool called mfoc to dump the keys and data off the card. From there, he was able to determine that the credit for the vending machines was stored on the card itself, rather than on a remote server.

This means that it’s simple to change the values on the card in order to get free credit, and thus free snacks. However, [Guillermo] wisely resisted the urge to cash in on candy and sodas. When totals from the machine and credit system were reconciled, there’d be a clear discrepancy, and a short investigation would quickly point to his own card.

He also managed to successfully clone a card onto a “Magic Mifare” from Amazon. In testing, the card performed flawlessly on all systems he tried it on.

It goes to show just how vulnerable some NFC-based access control systems really are. RFID tags are often not as safe as you’d hope, either!

Coin Acceptors Are Higher-Tech Than You Think

April 10, 2022 by 16 Comments

Coin-operated machines have a longer history than you might think. Ancient temples used them to dispense, for example, holy water to the faithful in return for their coins. Old payphones rang a bell when you inserted a coin so the operator knew you paid. Old pinball machines had a wire to catch things with holes in the middle so you couldn’t play with washers. But like everything else, coin acceptors have advanced quite a bit. [Electronoobs] shows a unit that can accept coins from different countries and it is surprisingly complex inside. He used what he learned from the teardown to build his own Arduino-based version.

For scale, there is the obligatory banana. Inside the box there are several induction coils and some photo electronics. In particular, there are two optical sensors that watch the coin roll down a ramp. This produces two pulses. The width of the pulse indicates the diameter of the coin, and the time between the pulses tells its speed.

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