How to measure voltage on an android

#12

Joined Nov 30, 2010
18,210
Connect the black (-) lead of the meter to, "ground" or, "common". Connect the red lead of the meter to the point you want to measure. Something in the range of zero to 5 volts is to be expected.
 

Thread Starter

Pavle

Joined Dec 6, 2015
42
I connected black wire to the ground and red wire to red wire but is not showing anything on display.
 

#12

Joined Nov 30, 2010
18,210
I don't know the color codes of an Android or a USB connector. Perhaps some other person could help.
 

Lestraveled

Joined May 19, 2014
1,946
The connection to a Android in an input. Plus +5 volts should not be present. You might get some voltage on the data pins if there are pull-up resistors.
 

kubeek

Joined Sep 20, 2005
5,732
How to measure voltage at micro usb port on android with multimeter???
Which end of it? The charger or the phone?
A charger should give 5V between the outermost terminals IIRC.
A phone could be giving out 5V, but it just as well might not. That depends on the hardware of the phone and if it supports USB OTG.
 

kubeek

Joined Sep 20, 2005
5,732
That would be a little difficult since the battery voltage in cell phones is about 3.6 volts.
The USB OTG spec says 4.4V to 5.25V, so the phone obviously needs to do a boost conversion from the battery voltage. Not too difficult with modern minitaturization, but still a hassle, which is why not too many devices have this.
 

Lestraveled

Joined May 19, 2014
1,946
From https://en.wikipedia.org/wiki/USB_On-The-Go

It does so by periodically measuring the capacitance on the USB port to determine whether there is another device attached, a dangling cable, or no cable. When a large enough change in capacitance is detected to indicate device attachment, an A-device will provide power to the USB bus and look for device connection.

It will not provide power until it senses another device.
 

Thread Starter

Pavle

Joined Dec 6, 2015
42
I cut android usb cable and connected red wire with red wire,black wire with black wire and plugged in usb port to pc and micro usb port to android and multimeter says 4.76 volts.
 
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