Didn’t someone here say something about the WS2812’s drawing current while in an “off” state? It seems the LPD8806s do the same. I’m measuring 14mA on a string of 24 of them, or 5.8mA each. The LEDs are actually cut off from the same VCC bus, and I have the ICs turned “off” so the speak, doing nothing. Last command sent to them was to kill all output then I physically disconnected all the LEDs from them as well as the DATA/CLK lines.
Yeah I’m starting to look into using MOSFETS to gate the power to the strips. I have some projects coming up where I’d like true low power state for standby, and it would be nice to do that from the controller.
That’s how I’m cutting off power to the LEDs, using a 3A mosfet driven by the MCU (48 LEDs pulling 54mA each.) I kept scratching my head, wondering why the battery was slowly being drained when I left it connected with nothing else going on … till I measured VCC to the ICs.
I remember reading about power drain and MOSFETs in the OctoWS2811 writeup under the heading labeled “WS2811 Idle Power” http://www.pjrc.com/teensy/td_libs_OctoWS2811.html
I had a rude shock when I discovered that 12V 2801based pixels had a dark current of around 5ma each - my string of 100 was drawing half an amp when off. Of course that also means that even a display with a low brightness was not scaling down the power as I had expected. In the case of the 2801’s the dark current was especially bad because they don’t have a built in regulator to power the logic, so to work on 12v there was a zener shunt regulator on the tiny PCB of each pixel - ugh. In my case I went with a relay rather than a MOSFET, as I only needed to cut the power when shutting down (manually or if the lead acid battery got too low). If you are drawing just 14ma for 24 2812’s that would be much better.