12.71 mA

Posted on by crackingcontraptions_3voi0v

Although I really need to focus on getting the DW code integrated into the current system, I could not resist checking the power situation.

I hacked a USB wire

and inserted my Fluke ammeter into the red wire.  Could I somehow screw this up?

Then I configured the system simply to scan for BLE traffic continuously.  The results are not encouraging.

I guess the next step is to do a lot less, and try to figure out where the power is going.

David:

I got the board loaded and running and a 0.05 ohm resistor installed at R1001. All of the Nordic current should go through that resistor. I measure 0.124 mV, so 2.48 mA during MAIN SCAN_STARTING and briefly (maybe half a second) a much higher current of about 34 mA, I guess during MAIN SCAN_STOPPING. It’s too short to measure accurately with a meter and I haven’t hooked up the scope yet. The 0.05 resistor might make a voltage too small for the scope. Well, it *is* too small for the scope’s minimum range. A 0.5 or even 1 ohm resistor would be better.
I’m pretty sure about the 2.48 mA measurement. At least it’s not 12 mA.
11:27 PM (6 hours ago)
I was going to measure the total current but I don’t remember the function of the jumpers on the board to bypass the regulators and I need to go to bed. I can say that the FT232R is drawing about 1.94 mA. 

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