Hello, Im making a rvm or reverse vending machine to have cashless reward which can be claimed using qr codes save on phone by arduino and can be converted to goods (example facemask). My only problem is I don't have a single idea how can I save qr code images on phone and I don't know if arduino can be possibly create a one time use qr code.
First, I think I can connect the phone and the arduino by bluetooth connection as I don't need such fast and long connection. Is there anyone tried to send files from arduino (slave) to the phone(master)?
Second, I searched on google to create qr codes using arduino but I don't know if that was one time use and also if that qr code image can be passed through bluetooth.
lastly, I checked for printing qr code (//in case I can't send files to phone;) and it was way to expensive to acquire.
Also, I found a video creating a qr code reader so it wasn't part of the problem.
thanks in advance 