USB Voltage and Current Tester!! (version 2)

*UPDATED ITEM FROM PREVIOUS INSTRUCTABLE! (http://www.instructables.com/id/USB_Voltage_and_Current_Tester/)

Since it's sometimes necessary to check your USB ports for voltage or if you are curious on what kind of Current draw your devices might be pulling, it would be great to have something to check these.

Now you can.

Instead of just hacking apart USB cables and checking these readings with a Multimeter or one of the Pen Drive style voltage checkers, this instructable will give you a tool that is painless to use.

Moving onward.....

The old version of this was OVER 13" in length with the cable, this one is only 2 1/2"!!

*NOTE: I am not using the 2 DATA wires AT ALL!! There have been some comments to use it, but if using this adapter on a HD or FLASH Device, using the DATA lines and disconnecting power frequently could/will corrupt your DATA or Filesystem.

*PLEASE RATE & COMMENT*

Thank you!!!

Step 1 Parts!

First we will need a few things:
1. A Flash Drive case (or something equivalent, I used a USB Bluetooth dongle)
2. Sturdy Paperclip, maybe two
3. Wire
4. A Male and a FEMALE USB connector. I got the MALE plug from an old 128MB Flash Drive a co-worker donated to the cause (THANKS GARY!)
5. a small SWITCH from an old Flash Drive
6. Adhesive of your choice (I'm using Epoxy Putty and Epoxy again for this one
7. Spray paint of your choice to make it a little prettier (I use Duplicolor for Plastic & Vinyl)

Comments

[DojoMojoMofo]

This is a cool idea! I was looking for a way to check how much current an Arduino project was drawing, and your first version inspired me to make my own testing cable.

I made it much smaller than this though - I cut open an extension cable, cut the power line, then soldered a 2-3 cm wire to one end to extend it a little, and soldered each end to a 2-pin header and insulated the solder points with heat shrink tube. Then I stuffed most of it back into the cable body, and slipped a jumper - the type with the "handle" and visible metal loop - onto the header. (and then spent about 5 minutes continuity testing various combinations to be sure I wasn't shorting power to shield...) Now, to test current, I clip my probes onto the bare header so I don't lose my connection when working with things like flashdrives or smart devices like phones - if the probes short, no big deal, it'll just read "0," though insulated clips work just fine to stop that. Then, to test voltage, I disconnect the device, slip the jumper on, reconnect, and stick one probe into the hole on the jumper, and the other onto the shield of the USB cable - as long as your hub properly grounds the shield, I think it should read the same as the normal 5V to GND pin - it has for me when disconnected, and I've seen voltage drop on some devices with it.

I left the data lines intact, so I can see things like current draw when writing to a flashdrive, and in different device states, though the iPhone still realizes something is fishy and says charging isn't supported by the device when I'm in current measurement mode. My multimeter isn't top of the line though, and I wonder if it's impeding a little too much...

Anyway, thanks for the inspiration - this is really handy for debugging a USB device in progress when I'm not sure how much room I have to work with power-wise! I could put up a spinoff tutorial if you like?

[zack247]

i dont get it, how does it work?

[gmgfarrand]

Sorry, seems I missed a step. The usage is similar to the original project, except with this version, we have a switch and not a binder clip. http://www.instructables.com/id/USB-Voltage-and-Current-Tester/step6/Usage-Voltage/

[wibrle]

You Rock! This beats the h##l out of trying to use the multimeter straight to the computer. This is a definite build for me. Thanks for sharing.

[codongolev]

cool. I just made a usb christmas tree (I have an ible about it (that wasn't spamming bacause it relates(oh look, three parentheses))) and I just had to assume that there were 5 volts. this might have helped.

[lasertech]

OMFG!!!!! Can I BUY ONE!? I LOVE IT! If it's not available for sale, can I send a few bucks to a PAYPAL to donate to "the cause"? You have come up with some really cool stuff and I think it's worth buying ya a BEER!!!