How do you make long data wires reliable?
I’ve been lucky enough that all the projects I’ve created don’t require long data lines, but I’ve encountered in some tests massive noise when the data wire is longer than 50-60cm.
I did some research and tried many solutions, with mixed results. Sometimes it works, sometimes it doesn’t.
Any of you solved this and are able to push a solid data signal through, say, more than 2 meters from a Teensy?
I used cat-5 cable - ground/data on each twisted pair, so four lines of signal and I’ve gone up to 50 feet with that.
What type of LED ? 3-wire ? 4-wire ?
Are you using a voltage converter from 3.3V to 5V ?
@JP_Roy WS2812B, 3 wires. I’ve had the same issue with different voltage converters from cheap bi-directional ones to 74AHCT125. Sadly I don’t have access to the circuits I tested this on but this question has been bugging me for a while.
A while back I did a quick test with a long unshielded (~ 30 feet) of 3-wire (AWG22), the cheap, common type used to interconnect strips between a UNO and a single WS2812.
That cable carried the data, the GND and the 5V and that remote single LED worked perfect to my surprise. I did have close to 0.5V drop on the power across the distance and it was obvious I could not have more than 2-3 more LEDs before It would fail but it proved to me that the data line could be surprisingly long and still work well.
I think a long data line should not cause any problems for you specially if you follow D. Garcia’s suggestion of using a CAT-5 cable that has twisted pairs.
Are you also powering your strips via long small wires ?
Did you check the voltage drop on the 5V lines at the far end of your strips ??
I do 20 something feet with no problems from a teensy using twisted pair (ethernet) to ws2812’s, but you definitely need to move up to 5v.
The board I use is https://github.com/zekekoch/QueenController
I use the 74LS245N solution. Paul also sells a board for the teensy that does this, but he only support 8 lines and my board does 16.