ws2812.py

import array, time
from machine import Pin
import rp2

# Configure the number of WS2812 LEDs.
#brightness = 0.2
@rp2.asm_pio(sideset_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT, autopull=True,pull_thresh=24)
def ws2812():
    T1 = 2
    T2 = 5
    T3 = 3
    wrap_target()
    label("bitloop")
    out(x, 1) .side(0) [T3 - 1]
    jmp(not_x, "do_zero") .side(1) [T1 - 1]
    jmp("bitloop") .side(1) [T2 - 1]
    label("do_zero")
    nop() .side(0) [T2 - 1]
    wrap()
class WS2812():        
    def __init__(self, pin_num, led_count, brightness = 0.5):
        self.Pin = Pin
        self.led_count = led_count
        self.brightness = brightness
        self.sm = rp2.StateMachine(0, ws2812, freq=8_000_000, sideset_base=Pin(pin_num))
        self.sm.active(1)
        self.ar = array.array("I", [0 for _ in range(led_count)])
        
    def pixels_show(self):
        dimmer_ar = array.array("I", [0 for _ in range(self.led_count)])
        for i,c in enumerate(self.ar):
            r = int(((c >> 8) & 0xFF) * self.brightness)
            g = int(((c >> 16) & 0xFF) * self.brightness)
            b = int((c & 0xFF) * self.brightness)
            dimmer_ar[i] = (g<<16) + (r<<8) + b
        self.sm.put(dimmer_ar, 8)
        time.sleep_ms(10)

    def pixels_set(self, i, color):
        self.ar[i] = (color[1]<<16) + (color[0]<<8) + color[2]

    def pixels_fill(self, color):
        for i in range(len(self.ar)):
            self.pixels_set(i, color)

    def color_chase(self,color, wait):
        for i in range(self.led_count):
            self.pixels_set(i, color)
            time.sleep(wait)
            self.pixels_show()
        time.sleep(0.2)
    def wheel(self, pos):
    # Input a value 0 to 255 to get a color value.
    # The colours are a transition r - g - b - back to r.
        if pos < 0 or pos > 255:
            return (0, 0, 0)
        if pos < 85:
            return (255 - pos * 3, pos * 3, 0)
        if pos < 170:
            pos -= 85
            return (0, 255 - pos * 3, pos * 3)
        pos -= 170
        return (pos * 3, 0, 255 - pos * 3)


    def rainbow_cycle(self, wait):
        for j in range(255):
            for i in range(self.led_count):
                rc_index = (i * 256 // self.led_count) + j
                self.pixels_set(i, self.wheel(rc_index & 255))
            self.pixels_show()
            time.sleep(wait)