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Having this Qunali IR cam which has a USB connector left out at the assembly and comms only via LAN. Probed Data lines, and I got 0.9V fluctuated readings. It seems to send something out there.

IR Module Back of the cam Front of the cam

So was wondering if anyone could lead me to what values standard MicroUSB break-out lines would have.

  • U26 Seem to have tree pins with middle to ground. Maybe a two-way diode?
  • R4 is a pull-down resistor to the ground - Maybe 15k, looking at these guidelines? https://beyondlogic.org/usbnutshell/usb2.shtml
  • R1 cannot trace where it goes, but it doesn't look like a pull-up to 5V
  • D16, is that a Zener diode sign? Maybe 5V or a reverse polarity diode, as it is between the Fuse and ground.

enter image description here

I've populated F1 and L1. Where L1 was a breakdown of a USB port HDD, so it should be compatible. Planning to solder USB and see if there is any activity and, hopefully, will get some IR software that works over USB rather than this crappy quanli lan software

Gunay Anach
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    Prove me wrong, but that does not make sense. If there is nothing connected, there will be no transmissions. So nothing explains the 0.9V which sounds like a floating line. If this is a USB device, one of the pins would have pull-up to 3.3V. There would be no pull-down because that would indicate a USB host. The port may be only for debugging, and support for the USB port may not be implemented in the firmware, or it is left disabled. – Justme Dec 22 '22 at 11:57
  • Thanks for your response. I think data lines are connected to MCU. I populated the L1. I can pull the signal analyzer, but probably easier will be to just wire it up and see if the device manager will ping. I just want to make sure I have protection before I do so. I assume those components do that. – Gunay Anach Dec 22 '22 at 21:22

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