he PLUM IN(tm) is a device known as a “Hat” which is used in conjunction with a Raspberry Pi to interface the vending machine protocol(MDB) used by various devices including: Dollar Bill Validators, Coin Acceptors, Coin Dispensers, Smart Cards, Foreign Currency, etc. This allows the Raspberry Pi to handle incoming funds and can be used to store them electronically in the cloud when connected to the internet or to another local client.