I think I'm going nuts. I am trying to measure current on the Arduino with my multimeter. I have an Ideal 61-361 so I hook it up (even verified everything with the manual) and connect the leads to wires coming out of the 5V and GND pins on the Arduino.
On my meter I have two current settings. ADC & AAC (which I'm guessing means amps on AC or DC). I set it to ADC and get an overload. When I set it on AAC (just to try it), I get .008. This makes no sense.
Things I've tried.
Replaced the meter's battery.
Read the Arduino voltage which came out right
Read voltage on a AAA battery (correct).
Read current from AAA bat on ADC (got overload).
Read current from AAA bat on AAC (got 1.34~ - AAC fluctuates all over the place)
Got continuity from enclosed fuse (0.10)
Note: Battery is a rechargable (just charged) AAA NiMH 800mAh 1.2V
I'm lost, did I miss something? Do I need to replace the fuse anyway?
Hi,
you might want to try Google for "measuring current" to get the basic idea.
Answer to 4)
You short-circuit the battery with the meter. (See above)
Answer to 5)
when measuring AC-current the DC-part of the current of the signal is blocked. So you probably measure some ripple on the power-supply here. Switching to AC-current in DC-circuits is wrong, but doesn't break anything.
Try to learn not only how to measure, but what exactly are you measuring too. You must use ADC to measure DC currents.
If you put one test lead to +5v and another to GND you will get a short circuit current, that exceeds the 61-361 current limit (2.0 A). You can blow the protection fuse of the meter.
This current tends to infinite (I=V/R but R is near to zero, so I tends to infinite), but the battery has its own current limit, that is not infinite, but is more than 2.0A.