Designing a vending machine

Hi,

I'm new to the forum and the world of Arduino. So far, I love it :slight_smile:

I have a question which I need a really solid answer for. I appreciate it if you can help me.

I'm designing a vending machine prototype that will dispense a product after receiving a payment in coins.

The system needs to work like this: Consumer enters coins, the coin acceptor accepts the coins. Then a Servo Motor needs to turn in order to eject the product. A sensor then needs to guide the loading of the subsequent product. That's it.

I feel confident that I can design this using Arduino and the breadboard.

However, I don't know what the next step is. I don't think I can use Arduino's in my vending machine and have them operate for severals years trouble free.

So what do I do next?

Do I have some kind of micro controller designed or microchip?

I need a solution that will last for years without any trouble.

I don't think I can use Arduino's in my vending machine and have them operate for severals years trouble free.

What leads you to that conclusion? Will you be using a commercial coin acceptor? Where in the world will this machine be used? You'll have many, many product safety issues to address, both electrical and mechanical requirements. This not a trivial task, rather daunting actually.

The Arduino will last just about forever - for this kind of application you’ll likely want to create your own PCB with the ATmega processor (the heart of the Arduino) and all other components firmly soldered on. Keep that dry and free from mechanical stress and nothing will happen to it.

The hardest part is almost certainly going to be the coin acceptor. It’s got to work one time, every time, accepting all good ones and rejecting all others. That’s tricky. The second hardest part will be the dispensing part. Of course everything has to be really robust - who hasn’t ever kicked a machine in frustration over not working well? And it has to be loaded time and again, so strong mechanical hinges to open it, safe locks, etc.

martinn12005:
Do I have some kind of micro controller designed or microchip?

You have deep pockets?

You could consider a Nano. Prototype with a Uno, then use a Nano with the wires soldered for production.

You say you're going to use a servo- so the design is done? You didn't explain what the product is, so nobody here can picture the mechanism. If it's one of those spiral thingies a stepper may be better; if it's a door or flap, then yep maybe a servo

kenwood120s:
if it's a door or flap, then yep maybe a servo

Make sure that no amount of customer abuse to the flap can damage the servo - in other words, the servo can operate the flap (in whatever way) but the flap can't cause the servo to move.

Also make sure to test the prototype regularly during development with some typical users. I have always been amazed at how I have overlooked something that was the first thing a friend of mine tried.

...R