LED DESIGN FORUM: Putting the Smart Phone in control - Using apps in embedded systems to control LED lighting (MAGAZINE)

Nov. 20, 2009
An iPhone app has been developed to control a low-cost, two-wire, low-voltage LED color lighting system in the home, explains CARL MATTHEWS.
There is an iPhone app that allows you to use it as a spirit level or even drink beer from it—but have you ever considered using it to control the lights in your home or office? ML Electronics (MLE), a specialist design house, decided there was no reason why not, and wrote an app to prove it when they built a new LED lighting control system.

The iPhone and other smart phones are equipped with popular standard wireless communications protocols (such as WLAN and Bluetooth) and benefit from open software architectures with support for thirdparty software development, so in truth there is no reason why they can’t be used as a control module.

ML Electronics designers embarked on the development of a low cost, two-wire home LED lighting control system as a reference design to help us explore opportunities for using control technology to make our designs more sustainable. The design brief was to develop a low-voltage LED color lighting system that could be retrofitted into existing standard housings as a replacement for, or enhancement to, conventional lighting.

The system was required to use only two wires both for the low-voltage power supply and the control signals. In addition to allowing the system to be programmed using standard interfaces such as a PC over Ethernet, the designers set themselves the challenge of creating an iPhone application as an alternative. The project also demonstrates the efficacy of an innovative Power Line Control (PLC) protocol that runs over a 24V DC power line.

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This article was published in the Nov/Dec 2009 issue of LEDs Magazine. To read the full version of this article, please visit our magazine page, where you can download FREE electronic PDF versions of all issues of LEDs Magazine. You can also request a print copy of LEDs Magazine (available by paid subscription) and sign up for our free weekly email newsletter.