DIY Vending Machine - Guidance

[japasetelagoas]

Hey everyone,
Not sure if this post belongs here or at the Beginners section, in case I got it wrong, my bad.
Here's the deal:
I'm on the 3rd year of my Electrical Engineering course and turns out that we need to come up with some sort of product this semester.
We're probably going to use the following vending machine as reference:







So this is a "vending" machine that resides at the place that I work. Fastenal for those who don't know is a major parts supplier, from drill bits to whatever you can think of.

The way that we use it is by typing our company's ID number, then a password that we set up the first time using the machine, after that it asks what item # we'd like to get, press "#" the spring rotates and there you have it.

I've been to the US a few times and you can find these types of vending machines basically on every corner, that is not true in Brazil, especially in the countryside.

There's NO such machine at the city that I live in, and trust me, it's quite a decent small town.

The Project

Our group's idea is to come up with a smaller scale unit, maybe two or three different products, just a prototype.


In order to do so I'd like some tips regarding the following questions:

- Normally, what do these "final product" machines use as their logic processor? Specific microcontrollers, FPGA's?

- We're not going to implement paper money scanner on the prototype unit due to its price, maybe an RFID unit to simulate a "prepaid" card with the company that owns the machine, however, in case the time comes to use the money scanner, are there any recommendations when it comes to dealing with real money?

- A buddy of mine suggested using a TFT screen instead of a 2x16 LCD display, would that make things considerably harder?

- Last but not least, we have about 2 months to come up with the prototype, is it feasible?

Thanks a lot.

[ataradov]

- Normally, what do these "final product" machines use as their logic processor? Specific microcontrollers, FPGA's?

Absolutely anything will work. Something Arduino-like may be a good starting point, it will be plenty powerful for this.

You will also need motor-driver boards, which you most likely will have to design yourself.

however, in case the time comes to use the money scanner, are there any recommendations when it comes to dealing with real money?

Buy a scanner from a reputable company in your country. Scanners are currency-specific, so there is no generic recommendation.

- A buddy of mine suggested using a TFT screen instead of a 2x16 LCD display, would that make things considerably harder?

I'd stick with LCD. It is not the most important part of the project, and LCD is more than enough for this application.

- Last but not least, we have about 2 months to come up with the prototype, is it feasible?

Yes, provided that you don't need physical security and have easy access to materials and tools.

[jh15]

Regarding the legal fun, If I were to set up a pinball or vending machine in my town/state, there is a yearly fee. In my case, 75.00 a year for a pinball, not a cut of profits.

Oh, and from the peak years  that electronic video games that replaced pinball, I think there are sill laws for me that require no video games within so many feet of a school. LOL, will have to check it out.