Hey guys.

The project we are supposed to work on is a vending machine with these specifications:

• Machine accepts coins (5, 10, 20, 50 cents) and gives out exact change when needed.
• Name of the product is voiced out when a product is chosen.
• The vending machine can tell if a product is in, or out of stock.

Regarding the first point, we are stumped on visualizing a mechanism to allow the machine to give an exact change; specifically on the mechanical mechanism to allow the chosen coin(s) to flow into the dispense area.

As for the second point, a recommendation from you guys on a device to interface with that allows specific voices to be selected and subsequently voiced out through a speaker (or an alternative) will help tremendously.

Thanks in advance!


P.S. Hello INTI

 

How about a laptop with different MP3s that play when a trigger is recieved in the serial or parallel ports?

 

For the coin validator and for the change dispenser, it would be best to purchase an off the shelf solution to deter theft. There are plenty of OEM manufacturers that sell these type of devices, which have some fraud deterrent system already in place and have the ability to distinguish an acceptable coin or not.

as for the ability for the machine to tell when out of stock, the main controller can have a preset count of how many of each item it is holding, every time you "sell" or dispense a product you will deduct 1 quantity from total, when total reaches 0 you know you are out of that item, and to place a limit switch where the product is placed, so when there is product it will depress the switch, when it is empty the switch will be open, this will give you a redundant system for checks and balances to actually verify empty storage space.

For the machine announcing the product name or other messages, check out the line of chipcorders out there, you can pre record your own messages and have the controller select and play the necessary message when needed, see the site here >>http://www.isd.com/hq/enu/ProductAn...nsumerElectronicsIC/ISDVoiceIC/ISDChipCorder/



B. Morse

 

How about a laptop with different MP3s that play when a trigger is recieved in the serial or parallel ports?

I've thought about that but using a laptop would both take space and add a lot to the cost of project. A much cheaper alternative with the specific function would be sweet.

For the coin validator and for the change dispenser, it would be best to purchase an off the shelf solution to deter theft. There are plenty of OEM manufacturers that sell these type of devices, which have some fraud deterrent system already in place and have the ability to distinguish an acceptable coin or not.

Sounds like I could do with one, assuming it is cost-friendly for a group project.
Could you kindly lead me to where we can look for one of those?

as for the ability for the machine to tell when out of stock, the main controller can have a preset count of how many of each item it is holding, every time you "sell" or dispense a product you will deduct 1 quantity from total, when total reaches 0 you know you are out of that item, and to place a limit switch where the product is placed, so when there is product it will depress the switch, when it is empty the switch will be open, this will give you a redundant system for checks and balances to actually verify empty storage space.

Using a limit switch, that's a pretty good idea. We might use that instead of the earlier idea we had. Thank you.

For the machine announcing the product name or other messages, check out the line of chipcorders out there, you can pre record your own messages and have the controller select and play the necessary message when needed, see the site here >>http://www.isd.com/hq/enu/ProductAn...nsumerElectronicsIC/ISDVoiceIC/ISDChipCorder/

Looks promising, we'll have a look at them. Thanks once again.

 

I am not sure where you are located, but here is a link to some vending machine parts and suppliers >> http://www.vendingconnection.com/ypchangers.html

Your best bet to get one cheap, is to find a local shop somewhere near you that repairs vending machines, you may be able to purchase a refurbished one cheaper, since these things are very expensive!

If you were to build your own coin validator you will have to develop a system that can weigh the coin, measure diameter, and measure thickness of the coin, and also check to see if it is magnetic or not (all US coins are not attracted to magnets unlike some foreign coins, so they are non magnetic).


B. Morse