the model A already doesn't have an Ethernet Chip, and "stop checking" for USB won't make the USB hardware magically disappear, so even "in rest" it will still use about the same energy. An Active USB port will use energy, but most of it will go in sending signals to another USB device, without such a device attached no energy is used by trying to send those signals. So almost no power is saved by turning the USB stack off if already no USB devices are connected. Not that there are many other, better ways, to save some energy. Even when you use them all they won't lead to "a reduction in power by a magnitude or more." that is they won't allow the PI to run on a tenth of the current power.DominusPi wrote:I believe if you underclock it and make it stop checking for USB, Ethernet .. (Or whatever you don't need) signals, you will already considerably reduce the consumption.
If the technology ever exists I am sure you will get it.vk3pb wrote:I'd like to make a request for an ultra low power pi at some point in the future.
This is a baseless argument you might as well use a abacus instead of a calculator because it doesn't require batteries.Why? Think about the crystal sets you used to make when you were a kid. They were able to tune a local AM radio signal and provide enough power to drive a crystal earphone. If the power consumption of a pi could be reduced to these levels then a pi could be run off a simple coil and capacitor and a few diodes. There would be no need for a solar cell.
there are some microcontrollers today you could power from a "potato battery", like this one http://www.futurlec.com/News/Microchip/nanoWatt.shtmlMoosePi wrote:...could I power this new super duper Pi from a Potato ? http://www.crystalradio.net/contest/paul2.html
I get the impression that the computer builders of the world have been working on these performance/power/size issues since Babbage. They have done amazingly well so far.I want/need low power consumption and the power of a computer so that my applications can run for years but do very sophisticated things.
You are asking for something that doesn't really exist. High CPU power requires a lot of electrical power. Hence Smartphone batteries last about a day....vk3pb wrote:by aTao » Sat Nov 23, 2013 11:35 pm
"If you want minimal power, you dont want an OS, If you havent got an OS you dont need a computer, a microcontroller should do the job. All said, pick a different system.
Or run it from PV panels. In that case if you can see it, it will run."
You don;t always have access or room for solar panels for all applications. As for microcontrollers they could not handle sophisticated tasks like decoding digital radio transmissions.
I want/need low power consumption and the power of a computer so that my applications can run for years but do very sophisticated things.
I'm sure you've considered these, but they're just the questions that sprang to mind when I read this.vk3pb wrote:The idea I have is a remote controlled boat capable of self steering itself across an ocean and also receiving and sending messages and images.
Solar panels = extra weight + size. The less power I use the smaller I can make the craft.