PayPuk - RFID-based payment system

Greetings to everyone and welcome

We'd like to present you the PayPuk with the goal to simplify payment in bars and bill sharing in the form of a beer mat.

So, how does it work?

The operating principle can be easily explained using the example of a pub:

Every customer is given a PayPuk when they enter. If a chip is brought near the puk, it registers the chip. The chip contains information about the drink and price, which the Puk takes over and uses to create a list. This means that each customer receives their own list with the drinks that only they have received. The information on the chips is deleted after the first read, so there is no double booking. When paying, everyone can settle their Puk, which makes it easier to separate bills for larger groups, but it is also possible to simply pay together.

The PayPuk is therefore a simplified payment system.

And how do you make one by yourself? This is explained below.

Software

We're gonna start with the software, because the ESP is fixed inside the puk and you won't be able to program it except you're opening the housing again.

First you should upload the code "ESP32 Code" on the ESP32 with the Arduino IDE. You should change the string ESPID for every ESP you use, otherwise every ESP for the Puks will have the same IDs and the project won't work.

After the code is uploaded you can start the server.py. If it doesn't work you have to install python. In case it still doesn't work you need to install flask, there are several tutorials in the internet, it's just a python library. When the server is started two IPs are shown. To enter this in the ESP press the reset-button for 5 seconds. It then broadcasts it's own WLAN. Connect your mobile with this WLAN, go on the website from the ESP32 with the IP 192.168.4.1 and enter the SSID of the WLAN, the key and the shown IP on the server. With control and click on the IP you can open the site in the internet where you can sign in with your username. You can register the individual puks with the IDs configured on the puks via the EnteryourPayPukID. Now the Puks will detect the chips.

We also uploaded two json-files. The drink file is for configuration of the drinks on the chips, just enter the name, the price etc.
The user file is for registraion of users.

Hardware

Now, that the software works, you can start with printing. We have two step-files you can use to print the beer mat and the charging station.

A 3D-printed housing contains an ESP, the battery, the RFID reader and one LED. The following picture shows how the components are placed in the housing.

The wiring can be seen in the following picture:

Following these two pictures the hardware should work. Don't forget the screws, they're fixing the complete hardware. When everythings done your PayPuk should work.