PAGE 116 OF 150 · MICROCONTROLLERS & LEDS
Addressable LED Basics
Each LED has its own controller chip on a single data line.
LED SYMBOLTriangle points from anode to cathode; the arrows show light leaving the part.
Smart pixels
An addressable LED, such as the WS2812B, has a tiny control chip inside next to red, green and blue LEDs. Data goes in one pin, the pixel takes its own colour and passes the rest on.
Key facts
- Supply is usually 5 V.
- Each pixel takes 24 bits, 8 each for green, red and blue in that order.
- Data runs at about 800 kHz, so timing matters.
- A pixel can draw about 60 mA at full white.
Other types include the SK6812 with a white LED and the APA102 with separate clock and data lines. Put 300 to 470 ohms in the data line.
REMEMBER
One data wire controls every pixel along the strip.Try it yourself
Sketch the circuit on paper first, calculate the values, then build it on a solderless breadboard using a low-voltage supply. Measure with a multimeter before you make anything permanent.
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