Random spikes in short term battery status checks
Hello everyone,
I'm trying to check the battery charge every minute for MetaMotionR. The method I'm using is I subscribe to the battery signal and wait 1 second to get a reading then unsubscribe and wait a minute and so forth for 8 hours approximately. I noticed there are some random spikes in the charge and voltage. Please refer to https://imgur.com/ypf0rg5. I want to know what is the source of these spikes. I should also mention that the tag wasn't charging. Thank you
Comments
@mamdouh,
It's most likely a spike when Bluetooth or a sensor is turned on. For a micro second, something might demand a few milliamps of current to start running in so creating a spike. This is 100% normal.
Thanks, @Laura for the comment. Is this because of the way the tag is monitoring the battery?. I took a look at the schematics of the MetaMotionR tag and got the idea that the tag is monitoring the battery by feeding a signal from the battery using a voltage divider into an analog pin and then quantize the analog signal to get an estimation of the battery. Are my assumptions true?. Thanks again.
Yes you are correct. But dips will still happen when the bluetooth radio or sensors turn on.