WS2812 datasheet(40/98 Pages) RASPBERRY-PI

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Best Practices

Improper use can damage your NeoPixels. Before diving in, be aware of the following:

Before connecting NeoPixels to any large power source (DC “wall wart” or even a large battery), add acapacitor

(1000 µF, 6.3V or higher) across the + and – terminals as shown above. The capacitor buffers sudden changes in

the current drawn by the strip.

Place a 300 to 500 Ohm resistor between the Arduino data output pin and the input to the first NeoPixel. The

resistor should be at the end of the wire closest to the NeoPixel(s), not the microcontroller.

Some products

already incorporate this resistor…if you’re not sure, add one…there’s no harm in doubling up!

Try to minimize the distance between the Arduino and first pixel, so the signal is clear. A meter or two is usually

no problem. Much longer and things can become unreliable.

Avoid connecting NeoPixels to a live circuit. If you simply must, always connect ground first, then +5V, then data.

Disconnect in the reverse order.

If powering the pixels with a separate supply, apply power to the pixels before applying power to the

microcontroller.

Observe the same precautions as you would for any static-sensitive part; ground yourself before handling, etc.

NeoPixels powered by 5v require a 5V data signal. If using a 3.3V microcontroller you must use a logic level

shifter such as a 74AHCT125 (https://adafru.it/e5g) or 74HCT245 (http://adafru.it/1779). (If you are powering your

NeoPixels with 3.7v like from a LiPoly, a 3.3v data signal is OK)

Make sure that your connections are secure. Alligator clips do not make reliable connections to the tiny solder

pads on NeoPixel rings. Better to solder a small pigtail wire to the ring and attach the alligator clips to that.

If your microcontroller and NeoPixels are powered from two different sources (e.g. separate batteries for each),

there

must be a ground connection between the two.

Some of our projects don’t make the above precautions…these are typically small battery-powered devices and power

spikes aren’t a big concern. Any project with a lot pixels or a large power source should definitely include the power

capacitor and data line resistor.

https://learn.adafruit.com/adafruit-neopixel-uberguide

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WS2812 датащи(PDF) 40 Page - Raspberry Pi Holdings PLC