| Electronics > Projects, Designs, and Technical Stuff |
| Is this a USB port? (based on measurements) |
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| PP3331:
I have a four conductor connector on a device that is rumored to be a USB port. However, I don't know this for a fact, and do not want to connect it and blow it out. I was advised to use a multimeter in diode mode to check the various pins. Here are the results: On the port in diode mode: ---- red meter lead (gnd?) ---- 1.760v (data?) ---- 1.760v (data?) ---- 1.494v (+5?) Are there other combinations of readings I should make? Are these readings reasonable for a USB port? Obviously, I don't want to apply 5v to a 3v circuit or reverse polarity. Any thoughts? Thanks. |
| Gyro:
I don't understand why you have started a new thread on this, when you already have one running with the same information. :-// https://www.eevblog.com/forum/projects/safely-applying-power-to-unlabeled-unknown-usb-pc-board-connector/ |
| PP3331:
Because I now have the measurements and wanted to have the topic reflect that fact and the specific question which is different than on the OP. If you have thoughts on those measurements that would be much appreciated. Thanks. |
| Gyro:
But you put the same data in Reply #2 in the other thread! :-\ Frankly, you haven't given nearly enough information (in either thread). Nothing about what the "device" actually is. What's on the board (you clearly have access to a header). Photo's etc. There's no way I could tell one way or the other from the available information. If I were you, I would provide sufficient information (as above) in the other thread and request a Mod (use the Report to moderator link) to lock this thread. People (including Mods) tend to get ratty when they find themselves wasting time contributing to a thread, only to find that somebody else has posted the same advice on the other thread! P.S. Especially when you are now getting replies in the other thread. |
| PP3331:
I'll go back to the original thread for further discussion after this, but there isn't much to add. Photos are worthless (though I do have them) since it's a fairly rare and very tiny Molex. I have been "told" off the record that it's probably USB. I don't have access to the rest of the circuit (currently) because the owner doesn't want me disassembling unless absolutely necessary. So unless I just want to take a leap of faith and apply power (perhaps gradually) I don't have anything to really go on except the measurements I can take in situ. Thanks. |
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