A couple years back I fixed up an old table top vending machine for my kid's school to use as for fundraising through vending sales in the church/school. It's in a common area that's busy during church and community events, accessible to anyone inside the building. They had me eliminate the coin slot and put a QR code on the front for payment and attach a cash box to the side, and they run it on the honor system. That worked great for a couple years and then someone or several someones figured out they could take snacks without paying for them. Sadly that means they aren't going to refill the machine. Previously it raised quite a bit of spending money for the students to spend on fun school projects, while also teaching them about business / vending / raising money. They also loved the opportunity to line up after school and buy a snack. I'd like to enable them to continue offering it if I can.
I can tie into a pair of dry contacts inside it to fire a solenoid to enable the user to open a door on the machine and get product. As long as all the product is the same price it's easy to handle - close the electrical contacts and you can open just one door in front of the product you want and get it out, once it closes it won't reopen without the contacts being closed again.
My current idea is this: something where an unsupervised credit card terminal is available for people to tap to pay and after prompts it charges them, say, $2, and then fires the relay. Again, only one price, only one product per tap. Apparently if I got an iPad and Square terminal software there's a plugin that will fire a relay upon completion of a sale. I would prefer not to have to use an iPad. The Square Terminal does not support relay output. Are there any vending aimed terminals out there that have a reasonable buy-in, can handle the relay requirement, and don't have a monthly fee or minimum? I mention Square specifically because they have no monthly fee and charge 2.5% + 15 cents for a transaction. That's good. Many card services charge a monthly fee or have a minimum total per month in fees. That won't fly, this is likely to do $100 or so per month so a fee or minimum would eat up all the "profit."
Alternatively, does anyone have any suggestions on how to handle receiving payment? This is a very old, basic 70s tabletop vending machine that had a coin slot, which is long gone. A bigger machine is not in the cards just due to footprint, not to mention cost. I'm open to any ideas, but would prefer to make this machine work instead of replacing the machine. Not least of which is because I did a sweet purple and gold metal flake paint job on it at the kid's request.
And a pic prior to label application so you can see the glory:
I added led strips to light the machine. The coin release button was repurposed to make the led strips flash purple when you press it.
I don't know if this is in any way helpful, but for the last couple of Christmases the Salvation Army collectors up here in Ontario have had, in addition to the traditional container for cash, a Christmas-tree-shaped thing that accepted taps for (IIRC) $5, $10, and $20. Do you want me to poke around and find out more?
In reply to Stealthtercel :
Neat! Thanks for the tip, looks like they use Tiptap Pay. The devices look like they might work if I could get them to fire a relay but the problem is they charge $35/mo for the "rental" for one device. Ugh. I think that would eliminate too much of the actual benefit for the school. It's a promising lead, though.
Another thought: what if we just had them use Venmo to send money and had a Raspberry Pi or similar in the vending machine monitoring the Venmo feed and it unlocks when a payment is received? Something to look into at least.
In reply to dculberson :
It's definitely outside my wheelhouse, but I was going to recommend a Raspberry Pi.
The internet makes it seem like you can program them to do just about anything.
(And if it doesn't work out, you can always make it run DOOM.)
Thinking cash only would something like this mounted to the cash box work, connected to a raspberry pi that fires the solenoid if a dollar bill is inserted? Not sure how easy it would be to hack the output to the pi.
Or more simple, put up a security camera and post pictures of honor system abusers to shame them into compliance?
You'll need to log in to post.
