How to measure power usage of board powered with JST cable

Hi,

I'm much more of a software guy so maybe there is something simple I've overlooked.

I want to measure the power usage of my board (adafruit feather m0 adalogger: Pinouts | Adafruit Feather M0 Adalogger | Adafruit Learning System). I'm using the RTCZero library to put it into sleep mode and I need to know how much power I'm using/saving while in this mode as opposed to just running like normal.

Problem is, I'm powering it through a 2-pin JST cable connected to my battery so I'm not really sure how to get my multimeter in series with it. It's an adafruit battery wrapped in plastic so the only exposed conductor are the JST pins. Maybe I could buy another JST cable and make a yucky contraption to allow my multimeter to be in series with the + wire but I was hoping to do something without another parts order.

Is there an easier way to do this?

I use my scope but I have sensitive current probes and wrap the wire a few times. I think you will probably have to get a bit on the kluge side with some wire. Remember you can put the sensor (meter) in positive or negative wire, current is current at this level. If your meter does not go that low you can put a resistor in series shunted by a diode and measure the voltage across the resistor with your meter. The reason for the diode is to prevent it from slamming your meter when switching from sleep to active mode. You will have to measure both modes and change resistors. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil

The pins in most small connectors are held in there with tiny plastic locking tabs.
Lift it up with a needle, and you can just slide the pin out (without force).
Up to you what you want to do next.
Leo..

"I was hoping to do something without another parts order."

I often use pieces of cat3 phone wire strands to make temporary connections. For the male pins, I wrap a piece of bare ended phone wire tightly around the pin for a number of turns. Then i slide the coil off and either stretch it or mash it a little, so it is snug fit when pushed back on to the pin. For the female jack I bend over a bare end of the wire to make a snug fit, and then slide into the jack. Then I have external wiring to use with a multimeter.