This document summarizes how a Bitcoin ATM works. A phone connects to a card reader via Bluetooth which processes a payment using the phone's internet connection. The payment is then confirmed on the phone and a Bitcoin wallet on the phone sends the transaction to a remote Bitcoin address, completing the process. The Bitcoin ATM functions more like a vending machine and credits are given to Payworks for their Android SDK and card reader as well as Andreas Schildbach for the Android Bitcoin wallet, with all code available on GitHub.