I have a question about power. I’m working on a dress that’s 7 ws2811 strips (of about 128 pixels each (60 pixels per meter)), a teensy 3 and an nrf24l01+. Obviously this requires a lot of power. Right now I have a 5v 3 amp step down (pololu 2177).
If my teens hangs and I press the reset button then often it won’t reset. Are the ws2811 strips holding some capacitance?
@Mark_Kriegsman and I have been looking into similar issues. It turns out that, first off, there is a draw from the ws2811 chips, even when the leds aren’t showing power. The other issue is that when power gets tight, it appears that the usb controller on the teensy is the first to fall off the map.
Two things that we’ve done to work around this in our own projects is 1) have a 2-5 second delay after powering up to give us time to install new software onto the device while working with programming it. 2) make sure to have a way to cut off the leds from the teensy itself, to give it a chance to do things. Something else that mark does is a slow ramp up from 0 to running level of brightness.
I’m not sure how the reset button on the teensy is wired - i don’t recall if it’s a hardware reset or if it triggers an interrupt that then needs to be handled by the device.
That helps. Thanks Daniel
Are you using one 3A step-down per strip? Even at that, you could only run at about 40% brightness. You may need to power each strip and the Teensy individually depending on what your supply looks like. If you can sacrifice the brightness a bit, I have successfully run 60 pixels off of one 4.4Ah Li-Ion battery. You may be able to run one of your 128-pixel strips off of that if you keep it to less than 50% brightness.
I’m trying to run the whole dress at 1/8th power off of a single 3amp step down. I like the idea of using a separate step down for the teensy. That sounds right on.