I wondered if we had a hardware issue, or a software issue, or both.
I just tried to copy your measurement process with the Nordic eval board.  Here’s what I did, and I’m not sure of my workings, so check me out.
Notice the last note.  Maybe that’s significant for us?
  • I looked through hundreds of loose resistors and found one that claims to be 10 ohms.
  • Then I kind kludged it across the current measurement pins of the PCA10001, using my meter probes, like this.
  • Then I ran my software and put the Nordic to sleep (allegedly)
  • My meter looks like this
  • Then I found an ohms-law calculator and plugged in some values.
Well doh!  1.2mA

I have to measure the voltage which is…. 

Watts = Volts * Amps, so the answer is 2.367 * 0.0012 = 0.0028404  or 3mW.  This is a lot more than the µW I was hoping to see.   So it looks like there’s a lot of stuff still switched on.

Learned something significant

I read up some more on power saving.  Having the debugger running has a huge effect.  Here is my experiment that proves the point.
I made a simple program that:
  1. turns on a LED
  2. waits for a button press
  3. shuts down.

When running in debug mode the voltage measured across the bridge is 12mV

If I disconnect the debugger, the shutdown voltage is 0.1mV = 0.0001V.  So the current is 0.00001A.
So the wattage is

2.367 * 0.00001 = 0.00002367 W = 24µW.   

That’s a lot better, but it’s still 30x what I should be seeing.

Ahhh!   And then it struck me.  The meter has pooped out.  What I need to do is use a bigger resistor in the bridge.  I wonder what that will do?
The voltage now seems to be down to 2.426V, and the sleep current now measures 0.2mV across a 100Ω bridge, so the current is 0.002mA = 2µA ??

So the math is now 2.426V * 0.000002A = 0.000004852W 5µW.

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