Raspberry PI for vending machine controller

Question

I am a softie, with little understanding of hardware.

I want to develop a vending machine controller, as cheaply as possible, while still being functional. I don’t expect heavy CPU or RAM usage.

To be compatible with standard peripherals, such as coin & note changers, it must have a URT. I guess that I just use a USB to UATR converter? Is that best/cheapest/are there any alternatives?

It will also need to drive some motors to expel the vended goods, and will have a keypad for ordering and a display (which display probably depends on price), and possibly a sensor to determine that items actually drop. Does this mean GPIO pins?

I would like to add wifi, for diagnostics, retrieval of sales data, upload of new firmware to the machine, and, in future, I might like to add RJ45.

Can anyone advise me what is the best way to go? Do I just take a Pi Zero and start adding shields, or is there a better suited model/peripheral combination? Sorry to be so dense.

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[Update] a mere five years later, all that you have to do is DuckDuckGo for raspberry pi mdb.

Answer 1

So I won't be able to answer your questions completely, but it looks like the requested features you're looking for has been done in the past. Here is what someone else has been able to do.

1. Vending Pi Board A) Gather data from DEX Input / Output Port (Vending Machine Side). B) Collect data from Humidity & Temperature Sensors inside Vending machine.
2. Stock Data (Total Sold, Product Price, Product Total Price).
3. Android Phone / Tablet used to download data from Raspberry Pi system via Bluetooth.
4. Stores data locally ready to upload to server or to upload to PC then to server (Web Interface)
5. Provides GPS location input for Vending Machine.
6. Check Vending machine location through GPS (Through Android Smart phone/Tablet)
7. On board Temperature sensor can control mini cooler fan for Vending Board system.
8. Status LED’s for error checking / troubleshooting.
9. 2 micro switch to provide basic control ( shutdown, reboot)

It looks like they have a project page that outlines the entire process, and how it can be done again.

Here is the main URL
Here is their project page, it looks like they sell the Raspberry pi already pre-configured

If this isn't an acceptable answer, I can continue dredging google to find what else you might need.