Raspberry Pi Forums

In lxterminal how can I measure the amount of ma my rpi is receiving. I would like to know this because I just bought a 5v mobile device battery. It's packaging did not state it's ma out put so I would like to see if any one can tell me how to get a reading from the lxterminal on the rpi.

Hi,

rpiswag wrote:I would like to see if any one can tell me how to get a reading from the lxterminal on the rpi.

http://www.raspberrypi.org/forums/viewt ... 71#p562971

Additionally (if not readable from the message from the link): RasPi does not have embedded self current consumption feature.


Best wishes, Ivan Zilic.

rpiswag wrote:In lxterminal how can I measure the amount of ma my rpi is receiving. I would like to know this because I just bought a 5v mobile device battery. It's packaging did not state it's ma out put so I would like to see if any one can tell me how to get a reading from the lxterminal on the rpi.

you cannot measure the current consumption the PI uses (not "receives", thats just the wrong terminology) without adding complex hardware designed explicitly for that purpose, the software that reads out that hardware is largely irrelevant, but must be written nevertheless.
Its easier to simply use a multimeter.

I thought this was a slick little item from Adafruit; an inline USB power meter with serial output. It won't get any easier than this. Granted, the accuracy is not stellar.

To the OP: something like this will tell you what the Pi is currently using/consuming, not what your battery is rated at.

I guess an average lazy Rpi programmer just measures the current once with a multimeter and writes a typical value to a configuration file.

If you want constant on the fly power readings through terminal or ssh you will need to add some components to your pi.

From my measurements 4.3W was max with several items being powered off the USB ports, 1.1W while running but idle, and 0.5W while linux was halted. I would like to point out that I measured from the wall PSU and all and that my device is somewhat inacurate under 1W.