Stokes' ProjBlog

Two steps forward, one (exploding) step back. October 25, 2009

In the past couple of weeks, I managed to do a little more work on the soda machine hack. With the hardware to interface 110VAC relays to 5VDC logic done, the next step is to create a means of connecting it to the TINI390 board. This has turned out to be a little more complex than I’d anticipated, specifically because I don’t have direct access to the various I/O pins (at least not through its Java VM). The TINI is set up more like a microprocessor than a microcontroller; all the I/O is done by reading from and writing to specific memory locations, divided into several pages. The board has only eight general-purpose I/O pins, but it has a twenty-bit address bus and five usable “Chip Enable” pins. All communication with the on-board peripherals (such as the flash memory and probably the Ethernet) is carried over the same data pins, so anything I attach needs some capability to decode addresses in order to avoid reading or stomping on unrelated stuff.

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Further work on the Soda Machine Hack September 18, 2009

The W&B soda machine continues its march towards the Internet. Yesterday, Sam Gerstein (another W&B member) and I spent a couple of hours investigating its treacherous inner workings, figuring out specifically where the credit-emulating relay needs to go and testing the selection detection board.

Despite a couple of brief setbacks, the afternoon was a success. Virtually everything in the machine worked more-or-less as predicted. The CONTROL BOX did contain a couple of mysteries: a switch fixed in one position in by a steel plate and a couple of screws, a relay not connected to anything whatsoever, and color-coded wires that didn’t seem to match the schematic. Apart from those, however, it was fairly spacious and tidy inside. The machine had apparently been modified modified so that every item is the same price, so only one of the four circuits that denote credit is actually in use, and shorting this with the ‘hot’ connection registered as money having been deposited. The relay board will be easy to integrate.


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‘The Soda Machine Hack Project’ September 4, 2009

Willoughby & Baltic has acquired a vintage soda machine; if I were to guess, it dates back to the late 1950s or early 1960s. It’s a massive steel box with a wood veneer front, its sides an industrial non-color. In contrast to more modern machines, its only text is the words Cold Drink in small, white-on-black, sans-serif lettering above a narrow, horizontal window displaying a representative can of each beverage within. I should have thought to photograph it, but I was distracted by the interior. Inside, the machine is a wonder of space-age technology: as you can see from the schematic, everything operates on 110V AC line current, and its works are almost entirely electromechanical relays and solenoids. Frankly, it’s pretty cool.

Of course, the first thing that needs to be done to the machine is connect it to the Internet. Why? I don’t know. I’m only interested in the ‘how’ at the moment.


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