If you're using an iOS based device, we've made your life easy with our BlueFruit application, which is available in Apple's App Store.

This free iOS application allows you to send or received UART messages between your iOS device and the nRF8001 (select UART on the home page), or toggle pins from the iOS UI setting them to input, output or as PWM (select Pin I/O discussed in the next page)

UART Echo Demo

This UART is basically the same as nRF's but its a little more like a terminal window instead of a timestamped log.

The echoDemo example sketch allows you to send and receive simple messages using Serial-esque style commands, and the data will be displayed on both BlueFruit on the iOS device and the Serial Monitor on the Uno.

After programming the Uno with the sketch, you can open up the Serial Monitor (make sure it's set to 9600 baud!), and then open up the BlueFruit application on your iOS device and select UART on the home screen. It should connect!

Now, any data that you enter on the iOS device or the Uno will be transmitted to the other device as long as the connection is open:

The corresponding BlueFruit output can be seen below, where the red message is incoming data and the blue message is outgoing data.

Click the HEX button in the top right to switch over to hex display mode instead of plain 'ascii' mode