I’m using a SK6812 strip with 144 leds/m
PixelBlaze v2.7. Firmware is version 2.25.
Power is supplied via USB.
If I have the PixelBlaze powered without the led strip connected everything appears to work fine. I can pull up the web interface, change patterns, refresh, whatever.
When I connect the led strip the selected pattern will run for about 10-12 seconds and then everything freezes and becomes unresponsive. The led’s that were illuminated stay lit but no longer change. The web interface no longer accepts input and if I refresh, it times out.
Are you using the 5V from the USB to power your LEDs? The USB current capability will be exceeded when too many LEDs become lit, resulting in a voltage drop low enough to cause a malfunction of the PB.
From what I’m finding online each SK6112 LED draws approximately 40~60 mA with RGB at full brightness. With a density of 144/m I have a total of 288 LED’s. That puts my power requirements at 17,280mA and 86.4Wh. If I don’t want to exceed 80% of the power supplies capability I’m looking for something that puts out 5v, 20A, 110W (numbers are rounded).
If you’re going to protect yourself from full-brightness conditions, may as well do it fully, which is to say you’ll want to make sure you connect power to both ends of your 2m, and possibly the middle as well, if practical.
Power supplies like that are rated for a current output at a certain temperature (usually room temp) with adequate ventilation, and must be “de-rated” for lower current output capability when used at higher temps, such as when there is limited convection airflow or higher ambient temp. With that 40A supply, you have a lot of headroom from 20A, but definitely don’t put it inside an unvented enclosure.
With such a low voltage / high current situation, you’ll need consider the wire gauge and length of the connection from the supply to the LEDs. It’s easy to end up with a voltage drop too far below 5V for the LEDs to work. As @jeff suggested, you can run three 5V and three Ground wires from the supply to multiple points on the LED strip. Just ballparking, if the supply is very close to the LED strip, 3+3 5V and Ground wires of 18 gauge should be ok.
