RE: Current measurement in nRF51422 Development Kit

Stefan Birnir Sverrisson — Thu, 18 Feb 2016 20:00:29 GMT

That is correct, you should cut the SB9 solder bridge in the image with a sharp knife. Cuttin the bridge enables current measurement with an ampere meter on the "nrf currrent ceasurement" pins. You can measure the resistance between the ends of the SB9 solder bridge to verify that it is successfully cut

RE: Current measurement in nRF51422 Development Kit

10Hsin — Wed, 17 Feb 2016 15:50:01 GMT

Hi, I would like to ask that cutting SB9 means cut the area in this image ?

RE: Current measurement in nRF51422 Development Kit

Stefan Birnir Sverrisson — Tue, 11 Aug 2015 09:15:23 GMT

Perhaps you can find useful information in the current consumption guide.

To measure the current, you could capture a single connection event like in your first image and try to find some averaging function in your oscilloscope, and perhaps do the same for multiple connection events if you want to see average current consumption over a longer time period.

Mounting a resistor on R6 and measure voltage to see the current consumption is however not a good method to see ultra low currents of a few microamps, e.g. to see what the sleep current is. To measure the sleep current it is better to use a multimeter that is capable of measuring microamps, and measure the current directly, as described in method 2 on page 18 in the user guide. If you choose a long advertising/connection ineterval (e.g. 4 seconds) then the multimeter will have enough time to stabilize the reading of the current consumption and you will see the magnitude of the sleep current. Also, if you choose a very short advertising/connection interval (e.g. 20ms) then the multimeter will read the average current consumption. For reference, I use this multimeter which does the job just fine. On second thought, perhaps a multimeter with autoscaling would be more convenient.

I measure the current often with power analysis tool From Agilent/Keysight where I can see the waveform and accurately read the current consumption at any moment, low or high current, and also measure average current, but that is a very expensive tool.