Bluetooth 4.0 as a prototyping tool

Demonstration of rapid hardware/smartphone prototyping with Bluetooth Low Energy

Published
July 2, 2012
Reading Time
3 minutes

how our Bluetooth platform works

When the iPhone 4S launched in October of last year, it shipped with a feature that has yet to be fully utilized. That feature, Bluetooth 4.0 (also known as Bluetooth Low-Energy) is also in several new Apple products including the iPad 3 and MacBook Air. It is not unlike previous versions of Bluetooth, but it has some notable advantages that make it ideal for certain applications:

  1. It is actually low-power (as the name suggests). How much? Bluetooth 4.0 consumes half as much energy when active and transmitting, and 1/100 the energy when sleeping.
  2. The pairing process is simplified. Pairing is now quicker (down to 0.1s instead of 2.0s) and can be done from within an iOS app (instead of having to go through Settings). No complicated handshaking. Just press a button within the app, and you’re paired for good.
  3. Once paired, the Bluetooth device can wake up the iPhone or iPad with a pop up notification, even when the app is in the background. This could be a huge behavior changer for Bluetooth devices.
  4. Getting data in and out of the iPhone is no longer constrained by the Classic Bluetooth profiles, a reliable internet connection, the headphone jack (that so many companies have commercially hacked), or Apple’s proprietary 32-pin connector and their expensive MFi Program.

The more we talked about this with our colleagues, the more we realized how useful it would be as a rapid prototyping tool for wireless, short-distance communication. Bolstered by the Internet of Things, one can easily come up with applications for Bluetooth.

Many folks here at IDEO know how to quickly get something up and running on Arduino, so we figured we should make an Arduino shield for a Bluetooth Module. Moreover, instead of Bluetooth-to-Bluetooth connection (which can be mimicked using Xbee radios), we focused on Bluetooth-to-iOS.

Kyle Doerksen bought some nBlue Bluetooth Low-Energy modules, designed a board, and got it produced. In parallel, I dove into the command set for this module and started writing an Arduino library to interface with this specific board and module. Dan Goodwin jumped in and focused on the iOS side. Knowing the difficulty of writing iOS apps, he created an iOS platform where one can simply write a webpage (some HTML + Javascript) to communicate to the Bluetooth device. Because we’re connected via a server, we can open up the page on any web-enabled device to interface with the Bluetooth device (as long as one device is connected via Bluetooth 4.0)

In a few hours, we hacked up a small RC car, replaced its guts with an Arduino Pro Mini, and now have it controlled by iPhone.

Admittedly, this hardly takes advantageof Bluetooth 4.0′s real power, but it shows how quickly and easily it is to prototype hardware paired with an iOS device given the right tools. This reduces prototype cycle time and makes it easier to figure out what the human experience should be. That’s really where we as IDEO want to be focusing our time.

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