Payment solution

Hello everybody

I wanna start this topic by saying thanks for such a good community:)

Me and my friends have a Diving club where one of my friends have bought a air Compressor to fill up our tanks.

And for making payment easy it could be nice to have some payment solution . maybe a RFID chip each Club member has with credits on or something like that. my idea is that when someone pays somehow (RFID credit maybe) the Air Compressor can be started for 20 minutes to fill up one tank.

Can this be done with a arduino?

Or does anybody else has an idea?

Many thanks in advance.

Leon

Should be doable. There are RFID reader/writer modules compatible with Arduino.

But I think you would also need some kind of database, and some way to handle monetary transactions. The standard Arduino has very, very limited memory for such applications.

Vidoco:
Me and my friends have a Diving club where one of my friends have bought a air Compressor to fill up our tanks.

What would be wrong with a simple honesty box among a group of friends? Throw £1 (or whatever) into the box every time you take a fill of air.

...R

The first problem I see is having pockets in your wet suit for an RFID tag.

I can see the use of a keypad.
You press in your ID or tank ID or some such

as for run time, I hope everyone has all the safety training on filling tanks and such.

I think I would require a TANK ID as part of the process.
you would have to get your tank listed in the data base with date of most recent hydro so if your tank is out of date, you cannot fill it.

Nothing more exciting than 80cu ft of 3,000 PSI tank rupturing, loads of fun !

That adds a bit of additional safety... water level. fill in water
When you place the tank to be filled in the water, the existing tank pressure and water level would be taken
When you fill, the new pressure and water level would be taken. a mini-hydro of sorts. not 5/3rds, but if you have excessive expansion, it would indicate a problem.
The database would record your use, and tank.

Also, with existing pressure, it would be neat to find out how you use air.

Hello thanks for answers.

In denmark we pay around 8 Euros for filling a tank up no matter the start pressure. same way i wanna build a system so that people can come and get their tanks filled up. but in that way we need a payment system. i think RFID chips would be a good solution with a database, but i really dont know how to build it myself.. i need someone to help me. im gonna pay for it offcourse.

Eight euros?
That’s about seven pounds, or 60kWh, even at domestic rates.
That seems a lot for a fill!

Vidoco:
but in that way we need a payment system.

In the world I live in that would mean that you expect your friends to cheat. I would not expect that - or else they would not be friends for long.

i think RFID chips would be a good solution with a database, but i really dont know how to build it myself.. i need someone to help me. im gonna pay for it offcourse.

If you just want someone to write a program for you please ask in the Gigs and Collaborations section of the Forum.

However there is a great deal more to a system involving money than simply writing some code. It will need a lot of checks and balances so you can be sure the friends are not cheating and so that you can prove to your friends that you are not cheating them.

Also payment for a service brings with it legal responsibilities some of which are mentioned in Reply #3.

...R

There may be space for an Arduino here, but it's just part of the solution.

A way to read an ID code and open the tank (that's an Arduino job).
A way to communicate this to your payment system (can also be the Arduino - various ways of communication, even offline and asynchronous through records on an SD card) - both to request authorisation to open the valve, and later to record the fill has been done.
A way to record the number of fills, the cost of those fills, issuing invoices, recording made payments. This is not an Arduino job, this is a PC application thing.
If using this SD card recording: a way to update the SD card with the latest authorisations, and to read the data into your database.

All in all it's a pretty complex system.

Of course it's impractical to ask people to through money in a box when they're wearing wetsuits and presumably don't have their wallet at hand.

A much cheaper and possibly even more reliable solution is a piece of (waterproof?) paper with a list of names where people simply place a tick behind their name when they fill up their tank, and use a spreadsheet to record payments due and payments received.

One of the reasons to require a tank ID is because of the different pressures. putting 3,500 PSI into a tank that is rated for 2,500 PSI is dangerous.

putting 2,500 into a tank rated for 3,000 is just not getting a fill.

as for the idea of knowing the starting pressure. if you dove, you would know that you do not always use the whole tank. no one cares, but if you are going to go to the trouble of adding electronics, no reason to not actual gather data.
there is no discount if you top off a tank that is at 2,700 and you want 3,000,

Most of this would be eliminated if you sold tokens or a key-code in the dive shop. You enter your key-code and get a fill.

as a comment, if would be cheaper to give fills away for free than to develop a payment interface. just sayin.