Expand outputs (74HC595)

Goal

Drive 8 LEDs with only 3 pins using a shift register.

Why it matters

When pins run out, you serialise: that is the principle behind every bus.

Steps

1. 01Wire DATA, CLOCK and LATCH to 11, 12 and 8.
2. 02Pull LATCH LOW, send a byte with shiftOut(), pull LATCH HIGH again.
3. 03Scroll the bits with shifts (1 << i).

Next tutorials

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  Breathe an LED from 0 to 255 with analogWrite().

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  Set LED brightness with the knob (10 bits to 8 bits).

• RGB LED: mixing colours

  Create any colour with three PWM channels.

• Smooth fade (sine curve)

  Make the fade look linear by using a non-linear curve.