Electronic – Special USB Port With “Sensor” Contact

contactpinsportsensorusb

I've bought these special upright USB Type A ports with a "Sensor Contact" (the stray pin I've marked "Sensor Contact Pin"). I've been Googling on how they work, as well as sent about a half dozen emails to the tech support guy at the company (FCI) they come from asking the same question(s) like "How does it work?" and "Do you have examples?", and gotten nothing back but "They have the same pinout as other USB A ports", but not any relevant, helpful answers.

So that's why I'm turning to you guys. My assumption is that when a device is plugged in, it provide +5V through the "sensor" contact, which I could hook to an MCU or transistor or something.

What do you guys think?

Here's the Mouser page

Front Face - USB Type A with Sensor Contact
Pins - USB Type A with Sensor Contact

Best Answer

[ I haven't come across a USB jack with a cable detection mechanism, until now.
So, the following is just a hypothesis. ]

This additional pin provides a mechanism for detecting if a cable is plugged into the jack, even if there is nothing at the end of the cable. Have a look at the pinout for the standard USB type-A jack. Notice that the sensor pin sits just above the standard GND pin. When a cable is plugged into the jack, it flexes the GND contact which touches the sensor pin. Essentially, it's a switch.

You can test easily this hypothesis.

  1. Check the continuity between the sense pin and the GND with a multimeter.
    It should be an open circuit.
  2. Then plug in a USB cable and check the continuity between GND and the sense pin again.
    Now it should be a closed circuit.

enter image description here

standard pinout of a USB type-A jack

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