Embedded wireless solutions company EnOcean is planning to show the first self-powered transmitter to work at 2.4GHz.
The radio isn't passive, the power to run the radio is generated through motion, light or temperature changes.
Specifically this takes the form of an electromechanical converter which is as easy to press as a light switch. The effort necessary is easily within the limits of a panic alarm button for the elderly and infirm.
With 0.7mm of travel, the converter produces between 120 and 140 microjoules, which is enough to send 32KB of data. Bandwidth is 125KB/s, but the burst is very short. EnOcean said it had tried piezo electric solutions but found them to be less efficient, bulkier and less reliable.
With a constant power stream, it has the ability to do two-way communications, and to foster development of this, EnOcean has produced SDKs for thermal, solar and mechanical power harvesting. Each contains the small power source and a DC step-up transformer to produce the 3v the radio needs to run along with the radio itself.
The SDK is aimed at corporates who will buy EnOcean chips in quantity but the firm is happy to entertain hobbyists whom they have identified as providing a good source of innovation, so the SDK pricing starts at under €50.
For example, you could build something where when you press the black button and a little sign lights up saying "Do press this button again".
The EnOcean self-powered prototype will debut at Embedded World 2014 in Nuremberg which has, as ever, been carefully timed to clash horribly with Mobile World Congress between the 25th and 27th of this month.
Hmm, Nuremberg or Barcelona? - that's a toughie. ®