rodw wrote: I'm not really convinced plasma is a good candidate for a USB camera. The maximum USB cable length is about 5.0 metres in the spec and I have first hand experience with failed USB links around that length (After I had cut the end off and passed it through the firewall of a vehicle.... then I had to rework it to add a powered hub under the dash, cut the end off and redo it! powering a 5V hub in a 12v vehicle is not fun!)
I found a premade 5.0m serial cable was not long enough to reach my Z axis control box on a 1200 x 1200 mm table.
So how would you go with a 1200 x 2400 or 1500 x 3000mm table?
Sure you can get USB extenders, I just saw an ethernet cable extender that cost AUD $629. You can get active cables often used in photo studios.
The other thing is that we do not need pixel peeping accuracy because good enough is near enough because a sheet of steel is typically slightly oversize.
A button for a laser pointer touch off is more practical I think.
Powered USB usbs are cheapest to buy.
Simplest soution is power Use
5V regulator LM7805 with any 12v power supply is the cheapest option,
moreover you can use copletely separate USB charging adapter.
If phill's plugin is working correctly. Would be great to have.
Otherwise just a black screen.
