I made a 10 ft extension cord between my Pixelblaze and my light strings but when I use it I get a little bit of glitching. The extension is 18 gauge wire but it’s simple three strand no shielding or twisted pairs. So it’s running 12 volt power, ground, data. I do have all the grounds tied together. I’ve avoided loops and things that could introduce interference but have not been able to get a clean enough signal even using simple static color as the pattern. When I connect the pixel Blaze without the extension I don’t have any glitching.
So I’m wondering if I should try a length of ethernet cable and if I could run the 12 volt through the ethernet as well. Right now I’m only running 200 ws2815 leds.
As for wiring the ethernet cable, would one pair be data/ground and could I use power/ground in the other three pairs so that the 12 volt came through multiple wires for less voltage drop?
The twisting of the data with ground you propose should help with data integrity, assuming you are above the minimum voltage for power required for your pixels, after voltage drop in the wiring. You can also try reducing the data rate in settings to minimum (250 KHz) if you haven’t done that already. I think it would be better to use the twisted pair in the ethernet cable for data and keep the heavier 18 AWG wire for power, though, and supplement the 18 AWG power wires with the remaining ethernet wires. Twist the 18 AWG power wires also, if you can. You might be surprised at the amount of voltage drop that occurs through power wires when the pixels are operating at maximum current, like when they are all white.
I run data and clock signals through 20 feet of 22 AWG ribbon cable from the PB controller to the first pixel in my setup and that works fine if I reduce the data rate in settings to 250 KHz. I run the power through 20 AWG, but that’s only 4 feet of length between each 16 pixel LED strip and a long, hefty power bus. I’m using SK9822, however.
Yes, you can do this. For the long data run the appropriate termination (i.e. matching internal resistance of the source to the cable impedance) is very important. If I remember correctly the impedance of the Ethernet Cable is 90 ohm. I hope, the PB has serial termination resistor but I am not sure what is a value. If it is a lot less than 90 ohm it is better to add an external resistor. It must be placed right next to the PB Data pad.
BTW, Data Rate is not a problem. The problem could be with very sharp rising/falling edges. That’s why an appropriate termination is very important. Slowing data rate very unlikely will change slopes of edges.
The 100% reliable way is to use RS-422<–>TTL converters on each end of the long cable, and run the RS-422 data over one of the twisted pairs. Or, you may have luck using a data signal repeater every few feet.