5 Replies Latest reply: Nov 6, 2013 9:48 AM by agrahambell RSS

Raspberry Pi Power Usage - Testing?

wallarug Level 15

Has anyone done any power usage testing with the raspberry pi and/or its official camera board?


I am wondering exactly how much the camera uses when it is in use and when it is idle for a project that I am working on.  No-one on the other forum seems to have completed power usage testing with the camera.


There is however some testing done with just the Raspberry Pi and those results are very interesting. 

http://www.raspberrypi.org/phpBB3/viewtopic.php?f=29&t=32955

 

Results:


For comparison the model B 256M (default clocks):

Idle (console): 0.372A 1.89W

Idle (lightdm running): 0.375A 1.91W

Running scp from SD card: 0.413A 2.09W


Model A (default clocks)

Idle (console): 0.113A 0.587W

cat /dev/urandom | gzip: 0.153A 0.795W


Model A (ARM=350MHz overvolt=0)

Idle (console): 0.111A 0.576W

cat /dev/urandom | gzip: 0.133A 0.691W


Model A (ARM=350MHz overvolt=-8)

Idle (console): 0.106A 0.554W

cat /dev/urandom | gzip: 0.125A 0.652W

 

 

 

Is there anyone who can test the camera and post their results... I am very interested.

  • 1. Re: Raspberry Pi Power Usage - Testing?
    wallarug Level 15

    Has anyone made any progress on this area?  I would really like if someone could test a model A and the camera recording a video, then taking a still.  I want to know if @JamesH 's estimates of 250mA - 270mA are correct for a battery powered project.

  • 2. Re: Raspberry Pi Power Usage - Testing?
    Level 15

    I don't have a model A, but I'll get you some relative numbers for a 256M model B with the camera operating that should give you some idea of what the additional power requirements are when using the camera.

  • 3. Re: Re: Raspberry Pi Power Usage - Testing?
    Level 15

    Ok, so start with a recent version of Raspbian with the latest 3.10.18 kernel, Raspbian has had all of the GUI and other unnecessary software un-installed, so it's basically running console only.

    This is on a 256Mb model B, ethernet is enabled, but no cable connected. Standard clocks, no over, or under clocking.

     

    Current
    Delta
    Description
    327mAidle, nothing connected other than PSU & SDCard
    327mAas above, plus HDMI connected monitor
    335mAas above, plus usb keyboard and mouse
    336mAas above, plus camera
    505mA169as above, running raspistill -v -o img.jpg
    595mA259 to 344running raspivid -v -t 20000 -o vid.h264.  note that there are peaks up to approx 680mA every few seconds, presumably as the data is saved to the SD card

     

    So on the face of it, if a model A at idle is 113mA, then approx 280mA when running raspistill, more when running video.

    I'm not claiming any great accuracy for these numbers, and there's probably ways to save power by not running the preview window, adjusting capture size and fps for example.  But maybe it gives you some idea of what to expect.

  • 4. Re: Re: Raspberry Pi Power Usage - Testing?
    wallarug Level 15

    So is that ~170mA for taking stills at full resolution?  and ~260mA when using video... which is what @JamesH said.

     

    That seems right.  Thanks for testing for me.  I hope you can get a model A one day!

  • 5. Re: Re: Raspberry Pi Power Usage - Testing?
    Level 15

    wallarug wrote:

     

    So is that ~170mA for taking stills at full resolution?  and ~260mA when using video... which is what @JamesH said.

    Yep, an additional 170mA on top of the idle current.  For a battery operated application, I'd be concerned about the peak load while saving video. At some point the battery might still be able to handle the steady state current draw, but not the peaks. Likely resulting in a corrupt sdcard.

    That seems right.  Thanks for testing for me.  I hope you can get a model A one day!

    No interest in a model A, I have more than enough model B's