How to measure voltage at micro usb port on android with multimeter???I connected black wire to the ground pin and red wire to VBUS but is not showing anything on display. Connector is connected to Micro B port and Micro B connector is on the cable end.
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1\$\begingroup\$ Is there a reason to ask this again? Without really clarifying anything? Duplicate of 206105. And, assuming that you have the cable plugged into the phone, and are measuring the other end, your phone isn't a current source... it is a consumer. \$\endgroup\$– R DrastCommented Dec 15, 2015 at 18:06
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\$\begingroup\$ Android is an OS. Presumably you mean a piece of hardware running Android, what is it? \$\endgroup\$– Leon HellerCommented Dec 15, 2015 at 18:41
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Normal cell phone or tablet usb ports will not output a voltage on the usb VUSB/VCC or GND pins. OTG usb ports, if supported by the phone, need to be enabled by grounding the ID or Sense pin, before it will attempt to output 5V on the VUSB line.
A USB OTG adapter cable is typically needed. As a test, I hooked up a OTG adapter cable and a non-enumerating usb voltage tester (Essentially a multimeter) to a Samsung Galaxy S4 and got 5.1V volts showing up.
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\$\begingroup\$ Even with OTG cable it will not be possible to check the voltage with a multimeter. OTG powers the slave device for a split second and cuts the power off if no attempts to enumerate were made. You'll need an oscilloscope to see that. \$\endgroup\$ Commented Dec 15, 2015 at 18:15
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\$\begingroup\$ I know that from experience with TI SoCs. I assume TI is following the USB spec. \$\endgroup\$ Commented Dec 15, 2015 at 18:19
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1\$\begingroup\$ @DmitryGrigoryev I just connected a OTG adapter and a non-enumerating usb voltage/amperage tester (USB Charge Doctor) with my Samsung phone, and it shows up 5.13V for several minutes now. \$\endgroup\$– PasserbyCommented Dec 15, 2015 at 18:22
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\$\begingroup\$ That's entirely possible. Here's my experience. Let me correct myself: "it may not be possible to see that with a multimeter". \$\endgroup\$ Commented Dec 15, 2015 at 18:28