Bluefruit LE Friend - Bluetooth Low Energy (BLE 4.0) - nRF51822 Capacitive Touchscreen The Useless Machine is a

The Useless Machine is a gizmo that turns itself off when you switch it on

but added many improvements:

reprogram firmware using any BLE-capable iOS or Android device

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Bluefruit LE Friend - Bluetooth Low Energy (BLE 4.0) - nRF51822 Capacitive Touchscreen The Useless Machine is aThe Bluefruit LE Friend is your new BLE BFF! This USB to BLE board makes it easy to get your computer talking to your BLE enabled phone or tablet using a standard serial UART connection. In it's simplest form, it works on the same principle as a common USB Serial adapter (the FTDI Friend, for example!). Any data that you enter via your favorite terminal emulator on your development machine will be transferred over the air to the connected phone or