I think there are two power requirements:

1) need to predict if/when power is about to run out, so I can pack my bags; 
2) need to measure DW power bursts.  
Counting coulombs isn’t really a requirement.  And in some senses having a calibrated measurement like Coulombs isn’t a requirement either, because I just need to know that improvements to the code are heading in the right direction power-wise.  
The other longer term requirement would be to give the user some idea of how much longer the battery will last – another hour, another day, another few days…
I’m saying this because there is always the assumption that the solar cell will not see light, and the “battery” really will go flat.

//Mik
On Wed, Jun 11, 2014 at 8:05 PM, David Carkeek <dcarkeek@gmail.com> wrote:

The only option I can see at this point for using with a solar cell is the LTC3805. Maybe the TI chip could be used but the LTC specs are a little better. I still need to be sure all the voltages can be supplied using it.

I wonder if we really need the coulomb counter. If there’s room well use it but if not – it might be a candidate for removal. To study power consumption replacing the battery with a large cap charged to a known voltage will be more accurate. The sample rate of the coulomb counter might not be high enough to catch the short power bursts of the DW1000 accurately.

Sent from my iPhone

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