# how can I figure out if 1-3V is flowing from something using household items?

Basically what the (unconventional) question says! I don't have a voltmeter at home. How can I fashion one, or use some kind of test to determine if current is flowing? I know it's a relatively low amount, so I'm not worried about hurting myself (I don't know how much current it will be), but I know that also may make it hard to tell. The device will likely be warm in general; it is powered by 5V. There will be other "outlets" on the device without voltage flowing that I can compare to. I don't care at all about the specific amount. I just want to verify whether it is or is not flowing (i.e. whether my code works), and I won't have access to the ideal tools over the weekend. Is this possible? Any ideas?

• The simple answer is you cannot! you need a VOM and or a current meter to measure these parameters. What code are you talking about? It would be best to rewrite your question with more details and what you are working with? I do not know the resources you have or your skill set so I cannot tell you another way to make the measurements.
– Gil
Jun 12, 2021 at 3:08
• voltage does not flow ... current flows ... voltage just is Jun 12, 2021 at 3:10
• your tongue may work ... put two AA cells in series ... put the two wires on your tongue ... you may be able to feel it ... i know from my childhood that a 9 V battery is easily felt Jun 12, 2021 at 3:15
• If you gave more details about your circuit we might be able to come up with specific ideas. Jun 12, 2021 at 3:23
• "whether my code works" - what is your code running on, and how will a voltage indication of 1-3V tell you that it 'works'? Jun 12, 2021 at 5:33

You could take a compass and place it over (or even near) one of your wires like in this blog post:

https://blog.doublehelix.csiro.au/confuse-a-compass-with-electricity/

It will deflect when current runs through the wire.

Here's a video demonstration:

To enhance the deflection you can wrap the wire around the compass several times.

You can install a magnetometer app on a smartphone and use that in place of a compass.

If you don't have a compass or smartphone available, you can make a floating compass with a needle and a magnet: