Whether you run a club or a hackerspace, collecting membership fees and accepting donations can be a pain. [MRE] from TokyoHackerspace has the solution, an automated machine that can accept cash from anyone who is walking by.
Members can choose to either donate or pay their membership fee even when the hackerspace administrator is not around. The interface consists of two buttons, an LCD display, a place to put your cash, and a thermal printer that prints out two receipts (one for you, one which goes right back into the box). One of the coolest parts of this build is the banknote validator, which can work with over 100 currencies (in this case, it is programmed to accept Japanese bills). Despite the simple interface, a lot of thought went into this build. There are backup batteries for the real time clock, an EEPROM to keep track of all the accounting, and an Arduino as the brains of the operation. If you take a look at the project page, there is a lot of information on the Arduino code, the PCB layout, how to interface with the banknote validator, and more! Check out the machine in action after the break.
We would love to see the banknote validator used in other projects. Have you used one before or built something similar?