Hi everyone,

Just a very quick simple question for you lot!
I need to extend my printer cable from laptop to printer.

Can anyone tell me do I need to use 4 strand cable or can I use 2 strand?

As the printer is powered by mains power, do I need to use the power lines in the usb set up or can I just use the data line?
I have plenty of two wire cable and wondered if that would be ok as it saves me buying more.

Don‘t all rush at once to answer.

Thanks.

 

How long does the cable need to be?
Go buy a USB cable.
Maximum length for USB 2.0 is 5m.
Use a USB hub if you need longer distance.

 

I would extend only the data pair with your abundant cable and try.
If does not work, then would add the 5V second pair to the extension. If does not work then, it could be too distant so retry with the short cable to ensure it is all still healthy and functional.

Once I wired the device internal 5V supply rail to the PCB power traces of its B type jack in a printer to try something and worked.

There is this gadget that can feed 5V from a wall adapter into the B jack end too :

----> https://www.audiophonics.fr/en/dc-p...or-dc-55-21mm-female-power-supply-p-8332.html

 

Thanks guys,
I only need to extend it like 3 meters, but as i have 2 core cable that’s suitable, it seems a shame to have to buy more cable.
I think I will just give it a go and extend the data only pair and see what happen.
I will post the results when I have finished.

 

Extend all 4 wires because even when not supplying power, the power wires provide the reference. And know that the limitation is due to the capacitance between wires, just like other data cables.

 

Just thought I would update this post incase it’s helpful for anyone else in the future.
For the Epsom printer I have, just using the 2 data wires didn’t work.
So I joined 2 old usb cables together, and it worked fine.

 

Certainly all four conductors are mandatory for USB communications to function correctly. Always, at least in the standard arrangements.

 

You are going to need at least three for any device. I have programmed USB on PICs without connecting the Vbus (5V) to anything. It won't work without the 0 V (ground) connection though. Some devices may use the Vbus wire to let it know that it is actually plugged in.

As stated in #5 the power wires are a reference. Normally when you connect any two devices with any sort of wiring no matter what it is you need a connection to both devices ground planes. Even though on paper they are both at 0 V that doesn't mean one's 0 V is the same level at another device's 0 V. It is possible there is a measurable difference between the two that can cause things to not work.

What kind of wire did you use for the two conductor? USB data lines are twisted and shielded for a reason. If you used just regular wire there is no guarantee it will even begin to work, or if you are very lucky it will work.

 

The USB cables that I have seen damaged appear to have 4 conductors of about#30 stranded wire, or possibly a bit thinner. Not good for much more than a voltage reference.

 

A USB powered device is allowed to draw up to 500 mA from the host for a bus powered device. Not much, but enough to run a simple device. I have a couple cables I cut the end off that have around #20 for power that I saved for projects, but the rest have been smaller to the point of being too small to work with.

Edit:

By simple devices I kind of meant small, hand held, and the like. While most USB devices aren't exactly simple, their power requirements are.