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jgarff / rpi_ws281x

Userspace Raspberry Pi PWM library for WS281X LEDs
BSD 2-Clause "Simplified" License
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WS2811 (12V / 400KHz) + Raspberry Pi ZERO W -> Random blinks + SPI not work. #440

Closed piotrGTX closed 3 years ago

piotrGTX commented 3 years ago

RaspberryPi Zero W (Rev. 1.1) WS2811 (12V 400KHz) Logic level converter (3.3V > 5V) GND of Raspberry and power supply is connected

On PWM & PCM when I run "test" script. Color wave is correct but red background blinks. When I try my own script I also saw random colors & blinks (but not all points)

On SPI colors are totally random. I can't see color wave.

I tried to change /boot/config.txt by adding: core_freq=250 core_freq_min=250

Then the SPI starts work but works worst than PWM & SPI.... (More blinks and random colors)

Maybe something is not ok with clock & 400KHz on RaspberryPi Zero ?

piotrGTX commented 3 years ago

When I run "examples/strandtest.py" on PCM

Xartrick commented 3 years ago

I had almost the same issue.

I used a 16V 1000µF capacitor between +12V and ground. This helps avoiding power spikes which could damage leds. Also, a 300 Ω resistor to avoid electrical noise.

You should wire them close to the ledstrip.

piotrGTX commented 3 years ago

I had almost the same issue.

I used a 16V 1000µF capacitor between +12V and ground. This helps avoiding power spikes which could damage leds. Also, a 300 Ω resistor to avoid electrical noise.

You should wire them close to the ledstrip.

I do not have 300Ω resistor. So I tried to connect two 500Ω resistors in parallel, but it works worse 😢 (more flashes). With 500Ω resistor does not work at all.

Xartrick commented 3 years ago

I'm no expert in electronic, but I think 500Ω might be too much and your ledstrip won't correctly pick up low and high signal. I'm using exactly a 230Ω.

Did you check you power usage? See if the power supply is following up.

piotrGTX commented 3 years ago

I'm no expert in electronic, but I think 500Ω might be too much and your ledstrip won't correctly pick up low and high signal. I'm using exactly a 230Ω.

Did you check you power usage? See if the power supply is following up.

Woow i try with these resistors and SPI with and it works! The last led is the wrong color but the others work perfectly :)

piotrGTX commented 3 years ago

Now SPI works without changing core_freq 👍