First attempts at WS2811

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Fyod

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I have some time off and finally decided to try out the WS2812 led strips I had lying around.
I got the 74H245 chips and all looks to be connected correctly with just one row of 15 leds first.
The problem I have is that I get blinking white leds and nothing else. Before I switched to RGB/400kHz in the Basic library, I got red blinking only. Not sure which freq. I should be using as I have no datasheet for the exact product.
Is my assumption correct that the supply I'm using isn't sufficient? I'm using one of those no-name notebook adapters that should be pushing about 1.5A, through a ~20V->5V lin. regulator also rated up to 1.5A.
Although I don't think 15 leds should be pulling that much, there seems to be a significant voltage drop as I'm only measuring around 3V on the supply whilst blinking.

Truth be told, I didn't have any resistors around 100ohm, so those are not in place as the documentation recommends.
 
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Virtually all WS2812 LEDs are 800 kHz.

Supplying enough power directly to the LEDs is critically important. Wire sizes matter greatly as you use more LEDs. Use the largest diameter, shortest length wires possible, and run them directly from the power supply to the LEDs. If you've done the power supply part well, you should see 5V at the LEDs with they're all off, and the voltage should not decrease by more than about 0.1V when they all turn on.
 
Thanks for the quick reply, Paul. I'll probably take the setup to a friend who has a bench supply tomorrow.
Wires seem fine, atleast in comparison to examples on the documentation on the main page, and they are run directly to the strip.
Are the resistors only important when dealing with more complex projects and video?
 
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