Agreed. That surprised me too.
Some relevant points:
- do we know if the RPi's kernel adjusts the clock speed to match system load?
- do we know anything about the RPI's power consumption external to the MPU package, i.e. has the dash for cheapness affected the power requirements of any of the other stuff on the board? Cheap bits don't necessarily have the lowest power requirements.
Well, the amount of MIPS per Watt is still a lot better than with Intel.
The Raspberry Pi is not suitable for really low-power applications (battery-powered long-life) but it works reasonably well in mains powered applications, certainly compared to a PC, even with a low-power processor.
It can - the effect on power is not significant AIUI, but i've never measured it.
There really is not much more to it outside the SoC - the memory POP chip and the USB Hub/Ethernet. You can disable this in software on a B though. That does save some mA, but not a wise move if you need Ethernet!
Get bigger batteries.
Gordon
Agreed. After posting that I had a look around on the PICAXE site, found that the chips come from microchip.com , range in size and weight from an
8-pin DIL to a 40-pin DIL package and typically draw a few tens of microamps when running - plus whatever the stuff they're connected to draws of course!
Yep. Or use a STAMP or PICAXE if you're really pushed to meet size and weight limits on battery-driven kit.
We still haven't heard from the O/P what kit he also intends to run. He mentions a camera and some 'sensors'. How much power will all this kit draw compared to the Pi. Also, the experience of the LOHAN people on The Register suggests at least *some* heat would be a good idea at high altitude. The Pi might not be able to boot if it gets too cold.
To quote from a story by one of my heroes... "Insufficient data for a meaningful answer."
This!
As usual lots of waffle and irrelevance but nobody seems to have asked any meaningful questions
how long is the flight? what sensors will be running? how much data to collect? how much telemetry to transmit? how high is the flight? will gps be needed? what is the max weight for the payload?
Sorry I didn't answer so long but I can't remember details because I respon sible for software. I asked my team and I am waiting for a response.
See you soon
Don't bother, those type of people want to ask you all kinds of detail but when they have all the responses they still have enough unknowns to not be able to make an exact calculation.
You asked a generic question that is good enough, and all those details are not required to explain what is possible and what is not.
It is your task to match the replies to your project, not theirs. For example, if it is possible to run the computer in an interval fashion.
That's fine. It's possible your team have done all the budgeting already. If the mission is short, then there may be little advantage in saving power. It's only an issue if you have a limited power budget and are flying for a long time to high altitude does saving every little help. The very cold temperatures at high altitudes affect battery capacity making power more critical.
Why don?t you write
Am 19.12.2014 um 19:08 schrieb mm0fmf:
your answer *below* the question?
My guess: You didn?t have enough time to have fun.
Have a nice day
Gregor
Whoosh!
Actually, you are the one whooshing...
Nope, I'm pretty sure it's you.
Janek Jaracz schrieb:
save variables and shutdown. restore after start.
And use a relais in the power supply which is controlled e.g by (elektor?) t-bord 8 and a timer board. see T-board 28 temperatur-logger in elektor 12.2014
Hermann who know no other way but interrupt power supply for reset a raspi in a case.
Yes. But be careful, there's a real chance that the switch + timer (+ rebooting Pi) consumes more power than an idle A+.
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