Going to try my hand at sniffing the data driving a WS2812 chain for some future projects, and I’m wondering if anyone has tried this or knows of any existing resources for doing this. I’m fairly confident I can implement it with some RP2040 PIO since I have some pi pico boards laying around. Web searches for the topic aren’t turning up much of use, just a billion tutorials for driving the bus.
My only concern that might pose a problem is if the GPIO pins introduce noise or create other issues on the bus I’m trying to observe.
The WS2812 only runs at 800kbps. That’s well within the capabilities of one of those 24 MHz FX2 based USB logic analyzers that you can get for less than $10. Sigrok has a protocol decoder for the WS2812 LEDs.
well, it’s more being able to detect long vs. short pulses, as it’s not the logic level but the pulse width that encodes the bits.
With a 24MHz sample rate, there will be 30 samples per bit. The narrowest a pulse for the WS2812 can be is 220 ns, which will be about 5 samples. That’s more than enough to decode it.