Yet another topic about WS2801 LED Strings, right? I'm trying to run 2x50 strings of these WS2801-controlled LEDs. But I just can't get it to run code properly. I'm trying to run the basic FastSPI/FastLED programs (blink.hex and cylon.hex, for example).
I'm running a Teensy 3.1; it's powered from the USB. The LED strips are connected in the middle, and powered by a 10A 5V wall power supply. I've hardwired a switch so that I can turn on and off the LEDs for final installation. However, I'm pretty sure that the problem comes down to GND.
I've definitely wired up the string in the correct direction - there's an arrow on the mini PCB which matches what I've wired up, and I currently have all the LEDs lit, in a random and flickering fashion. When I disconnect the clock wire, this random flickering stops and they remain on solid colours - CLK seems to be working. When I disconnect the data wire, all the LEDs turn off - DATA seems to be being sent? I'm just not sure how to wire up the GNDs.
Bizarrely, I managed to get it working last night for about 5 minutes, by wiring the GND of the Teensy to the screw terminal of the power supply; I could run blink.hex, I could run cylon.hex and it worked (so I know that these strips worked at some point). However I can't recreate this now, as I cleaned up some of the wiring connections and it's back to square one.
There are three power connections - one at the start, one at the end, and one at half way. The halfway and end GND connections are spliced together and connect with the start GND to the power connection, but as soon as I try to tie in the GND from the Teensy, I get a random result usually in the measure of a few LED's lighting in a random position in the string. As soon as I remove the teensy GND connection, the LEDs go back to being randomly flickering and colourchanging.
I was wondering if you could hint as to what might the issue be. Happy to provide pictures and whatnot of the wiring.
http://i.imgur.com/IUlxP4g.jpg?1 Shows all the LEDs lit up.
http://i.imgur.com/4LFt3AJ.jpg?1 Shows the wiring breadboarded.
Blue is GND from power supply. Purple is GND for the start of the strip, and Brown is GND for the middle/end (which have been spliced together). Orange is the (disconnected) GND from the Teensy.
http://i.imgur.com/eW6nO2s.jpg Shows the various connectors and connections. Left is the midconnector, middle is the end connector, right is start connected to DATA/CLK too.
webm.land Here's a short video showing the change when I connect Teensy GND to Power GND.
The program that is running on the Teensy should be sending one red blip along the strip, which isn't shown in either case.