How measuring amperage

[Radec]

Hello,

What is the best patrice to measuring amperage with my multimetre when my expension board and lopy run ?

Thanks in advance.

Radec

[reader-uk]

Hello,

No such thing as a stupid question, we all learn by asking.. :)

Measuring current with a multimeter uses a different process compared to voltage. Voltage is measured by using the multimeters probes in parallel, current (amperage) has to be measured in "series" and requires the probes to be configured accordingly.

A very good website which I recommend is SparkFun. They have well written guides (better than I could write), so rather than me trying to answer, I'll provide their link below...

https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter

Youtube also has good videos.
https://www.youtube.com/watch?v=P660hTqkGiY

As rough guidance, I've a Wipy 2 running Wifi, 5v LCD display with backlight, RS232 level shifter - less than 200 ma being drawn from PSU

[Radec]

It's OK thank you.

I try with the battery.

Yes, I try to measuring with wire in serie from JST female connector to expansion board JST port and it doesn't work.
But If I connect directly wihtout the multimeter in serie, it's work (logic, it's the normal postion). I think, it's maybe a false connection or the JST connector ?

Now, I test from JST female connector (from battery) to Vin and GND port. I have the amperage ~ 39 ma when the lopy running LoRa without Wi-Fi.

[robert-hh]

@radec Maybe also a wrong setting/connection of the multimeter. Many of them have separate ports for current and all other signals.