Not really a FastLED question…so forgive me.
I have a large string of APA102 Pixels that I’m powering from a set of 5V battery packs. When I apply power to the Strips, some of the pixels randomly turn on…sometimes it may be allot of random pixels and they sometimes overload the battery packs immediately. Is there any way to power them up so they are all OFF once power is applied? I’m having the same problem using a plug in power supply so its not so much a battery issue.
How many pixels total?
How many Amps can your plug in power supply provide?
Is the LED strip ground connected to ground on your micro controller? Grounds must be connected between the two or you’ll get random pixels flickering.
Try to get things working with your plug in power supply first (presuming it’s large enough for your number of pixels) before switching to battery power.
Also: do you have a large capacitor close to the strip?
bit over 2300 pixels, YES grounded to micro controller. i don’t have a cap on any part of the system…should try that. I wish there was a way to power them ON without them randomly assigning colours.
I just put a big cap onto the power rails and it doesn’t seem to do anything. Only way the pixels all power on is by chance that most of them start up non-lit-up and don’t drain the power supply. What am I doing wrong?
Are you injecting power every few meters so you can keep a consistent 5V all the way down the strip?
You could add a 1000uF 32V capacitor at those injection points also.
Also, what power supplies are you using? How many Amps do they supply? 2300 pixels is going to need 100A or more depending on how bright you run them.
@marmil cheers, yep im injecting power at about evey 200 leds. Ill add caps as u sugeat and see if that helps. Im also notrunning the entire system at full ball, i know it works it just doesnt power up properly.
You could use some P-Channel MosFets to provide power to the LEDs.
Option 1: use a push button to switch on and off
Option 2: use a I/O pin of your µController instead of the small circuit and use just the MosFet part
Make sure you programm a power-on sequence with reasonable delays in the setup()
Certainly use @marmil 's advice and use a Cap. I also add a few smaller ones in parallel (1µF, 100nF, 10nF). Those are faster and ‘eat’ the small spikes.
With 2300 LEDs you got a quiesence draw of 2300mA just when you apply power to them.
Have you got a picture of your installation you can share?
Cheers for the advice here is the thing in action https://www.instagram.com/p/--yRzYxDWW/
I ended up putting hardware switches on each of the power taps. Works just fine if i sequencialy power on the system.