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Guide To Designing Low Power Handhelds
randomErr writes "iAppliance had a nifty article about designing handhelds. As the state-of-the-art in low-power CPUs races forward, the CPU becomes one of the most critical components in the design of a handheld. New CPUs such as Intel's XScale, Alchemy Semiconductor's Au1000, and Transmeta's Crusoe provide the ability to scale clock frequency and voltage dynamically. As power consumption varies linearly with clock speed and as the square of core voltage, you'll want to have hardware hooks to be able to adjust both clock speed and voltage as necessary, based on device performance."
Palm systems are curently on top. They may only be B&W, but they get great battery life and do what most users need. Once you start entering the realm of music, that can be scaled over to an MP3 player instead of a Palm device.
However, once you start deciding to run higher end applications, give the machines net connects, etc. everything gets more complicated. Full color, integrated (or even unintegrated) 802.11b, sound and so on all drain batteries at an increased rate. My keyboard for my palmtop drains when it's plugged in, which is, obviously, why it's not plugged in all the time.
Battery life and functionality are both the keys. Is there a potential way to implement a self charging feature? Maybe harness the kinetic energy of movement to assist in charging the device? Most people with handhelds carry them everywhere. It wouldn't work well with high drain / low charge devices, like the Ipaq, Jornada, etc. which have charges of under 10 hours (at best) but maybe a system like this could achieve a few days or a week in a low drain device like a Palm m100.
I have no idea. Just a decidedly random thought that I had. Later.
Or one that combines such a self-winding pendulum drive with some solar cells and some of those nifty materials that convert thermal energy to electricity?
Maybe even some antennae that can absorb all the abundant radio/microwave radiation that cell towers, wi-Fi, bluetooth, high-power transmission lines, the sun, etc. etc. are constantly pumping out? Tesla's wireless power dreams finally realized!
I think that vastly increased use of such passive reclamation systems is about the only way that tomorrows electronic devices can manage to simultaneously get smaller AND significantly more powerful.
When Thales was asked what was difficult, he said, "To know one's self." And what was easy, "To advise another."
I really like FastCPU for PalmOS. I run it on my Treo. Its great to be able to overclock slow apps from 33 MHz to 66 - it makes a helluva difference, and, it doesn't lock up all that often.
The other cool thing about it is that I can underclock things like notepad or "to-do list" so they use less battery power while running.