I am learning how to build USB cables as a hobby.
For my early attempts, I did not attempt to shield the cable, I just skipped the bare shield wiring I've seen in other USB cables. However, recently I have found that some of my USB cables don't work properly (the usb device is not recognized on Windows) or some of them only work in a short period of time before the device is disconnected. So, I am now trying to include shielding in my USB cables.
I have tried crimping a bare shield wire to the USB housing at both the devices and host ends of the cable. Is this correct? The wire I use is 24/28awg and I also apply a silicone glue to prevent a short circuit.
What is the correct method of adding shielding into my USB cable builds? Is grounding the shield at both ends of the cable correct? Or should I just crimp the shield on only one side? Or not shield at all?
How I recently do my cables. It works however the connection isn't very good and a few minute later it disconnects.
Best Answer
No, the problem is your not using twisted pairs. USB uses differential signalling with an impedance of 90Ω (transmission line impedance). You also need a shield to protect against noise.