There was a time when a coffee vending machine was a relatively straightforward affair, with a basic microcontroller doing not much more than the mechanical sequencer it replaced. A modern machine by contrast has 21st century computing power, with touch screens, a full-fat operating system, and a touch screen interface. At Hackaday Supercon 2023, [Kuba Tyszko] shared his adventures in the world of coffee, after reverse engineering a couple of high-end dispensing machines. Sadly he doesn’t reveal the manufacturer, but we’re sure readers will be able to fill in the gaps.

Under the hood is a PC running a Linux distro from a CF card. Surprisingly the distros in question were Slax and Lubuntu, and could quite easily be investigated. The coffee machine software was a Java app, which seems to us strangely appropriate, and it communicated to the coffee machine hardware via a serial port. It’s a tale of relatively straightforward PC reverse engineering, during which he found that the machine isn’t a coffee spy as its only communication with its mothership is an XML status report.

In a way what seems almost surprising is how relatively straightforward and ordinary this machine is. We’re used to quirky embedded platforms with everything far more locked down than this. Meanwhile if hacking vending machines is your thing, you can find a few previous stories on the topic.