A Tweeting Vending Machine

[Sigurd] manage to obtain an old vending machine from his dorm. The only problem was that the micocontroller on the main board was broken. He and his friend decided they could most likely get the machine back into working order, but they also knew they could probably give it a few upgrades.

This system uses two Arduino Pro Minis and an Electric Imp to cram in all of the new features. One Arduino is connected to the machine’s original main board. The Arduino interfaces with some of the shift registers, relays, and voltage regulators. This microcontroller also lights up the buttons on the machine as long as that particular beverage is not empty. It controls the seven segment LED display, as well as reading the coin validator.

The team had to reverse engineer the original coin validator in order to figure out how the machine detected and counted the coins. Once they figured out how to read the state of the coins, they also built a custom driver board to drive the solenoids.

A second Arduino is used to read NFC and RFID cards using a Mifare RC522 reader. The system uses its own credit system, so a user can be issued a card with a certain amount of pre-paid credit. It will then deduct credit appropriately once a beverage is vended. The two Arduinos communicate via Serial.

The team also wanted this machine to have the ability to communicate with the outside world. In this case, that meant sending cheeky tweets. They originally used a Raspberry Pi for this, but found that the SD card kept getting corrupted. They eventually switched to an Electric Imp, which worked well. The Arduino sends a status update to the Imp every minute. If the status changes, for example if a beverage was dispensed, then the Imp will send a tweet to let the world know. It will also send a tweet to the maintenance person if there is a jam or if a particular slot becomes empty. Continue reading “A Tweeting Vending Machine”

Vending machine prototyping

[Vending Mexico] plans to design, build, and sell their of vending machines. You’ve got to start somewhere so they’ve built this prototype. It offers a range of vending features but was built with parts we’re used to seeing in hobby projects.

The one challenge they didn’t take on is the ability to identify coins and make change. You can see they’ve chosen to use a Coinco Guardian 6000 changer. But the custom circuit taps into the device, identifying how much money has been dropped in the slot, and controlling the coin dispenser to make change. Right now there is only one item to choose from; some packs of gum  stored in a cardboard partition with the typical metal corkscrew — driven by a servo motor — to dispense the product. Just below that partition there is a row of IR LEDs which have a complimentary set of IR phototransistors. The machine uses these to detect when product has dropped through. This way if your candy gets stuck you get your money back.

The user interface is shown off in the video after the break. It uses a set of seven segment displays for feedback. An arcade button is used to select the desired product. The video dialog is in Spanish but we had no trouble telling what is being shown off even though we don’t speak the language.

We can’t remember seeing other scratch built vending machine. It seems all of them have been hacks on older commercial vending hardware.

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Old school vending machine learns new tricks

Thanks to craigslist [Chris] got his hands on a soda vending machine circa 1977. It still worked just fine (because things were still built to last back then) but he wanted to add some super-secret upgrades to the beverage dispensary. Two capacitive touch sensors were added to override the need for coins for those who know where to caress the beast, and iPhone support means that frothy beer is just a touch away.

The capacitive switches are using the same QT100 chip we saw in the game of life from last year. The whole thing runs off of a Phidgets board which we’ve seen in the past using iPhone control to launch rockets. See a demonstration of the features in the clip after the break. We’d love to do a hack like this but the problem is once you’re done, you’ve got a vending machine sitting in your house.

Continue reading “Old school vending machine learns new tricks”

Age verification cameras easily fooled


Nice try, Fujitaka. They manufacture cigarette vending machines in Japan, and were all set to roll out a new system of age verification cameras on their machines, which would scan the face of the buyer to look for sagging skin, wrinkles, age spots, and other signs of legal smoking age. The system is easily circumvented, however: people with a photo of an older person clipped from a magazine can fool the machine by simply showing the photo instead of their own faces.

Another aspect to Japan’s cigarette control is the Taspo card, which is an age verified ID issued to smokers of legal age or older (20 years old is the legal age in Japan). Taspo cards are required for over the counter purchases, and the majority of vending machines require them as well. Relatively few machines are outfitted with face recognition systems, but many more are set to ship in the coming months. Fujitaka claims they are working on a solution by improving the face recognition software, but we think it would be a lot easier to simply check the background of the image. Since the camera is static and always pointed in one direction, the portraits it captures should always have the same background. Someone please tell Fujitaka we just saved them a boatload of R&D money… until Guy Fawkes masks become more popular.