ws2812/ws2812b.py

# Example using PIO to drive a set of WS2812 LEDs.

import array, time
from machine import Pin
import rp2
from time import sleep
import uasyncio as asyncio

# Configure the number of WS2812 LEDs.
NUM_LEDS = 256
PIN_NUM = 0
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 WS2812B: 
    def __init__(self, num_leds, pin_num, brightness, sm):
        # Create the StateMachine with the ws2812 program, outputting on pin
        self.sm = rp2.StateMachine(sm, ws2812, freq=8_000_000, sideset_base=Pin(pin_num))

        # Start the StateMachine, it will wait for data on its FIFO.
        self.sm.active(1)

        # Display a pattern on the LEDs via an array of LED RGB values.
        self.ar = array.array("I", [0 for _ in range(num_leds)])
        self.num_leds = num_leds
        self.brightness = brightness

    ##########################################################################
    async def pixels_show(self):
        self.sm.put(self.ar, 8)
        await asyncio.sleep(0.00001)
        
    def pixels_set(self, i, color):
        self.ar[i] = (int(color[1]*self.brightness)<<16) + (int(color[0]*self.brightness)<<8) + int(color[2]*self.brightness)

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

    async def color_chase(self, color, wait):
        for i in range(self.num_leds):
            self.pixels_set(i, color)
            await asyncio.sleep(wait)
            await self.pixels_show()
        await asyncio.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)
     
     
    async def rainbow_cycle(self, wait):
        for j in range(255):
            for i in range(self.num_leds):
                rc_index = (i * 256 // self.num_leds) + j
                self.pixels_set(i, self.wheel(rc_index & 255))
            await self.pixels_show()
            await asyncio.sleep(wait)

    BLACK = (0, 0, 0)
    RED = (255, 0, 0)
    YELLOW = (255, 150, 0)
    GREEN = (0, 255, 0)
    CYAN = (0, 255, 255)
    BLUE = (0, 0, 255)
    PURPLE = (180, 0, 255)
    WHITE = (255, 255, 255)
    COLORS = (BLACK, RED, YELLOW, GREEN, CYAN, BLUE, PURPLE, WHITE)
    

async def run(pin, sm):
    ws = WS2812B(10, pin, 1, sm)
    ws.pixels_fill(ws.RED)
    while True:
        await ws.rainbow_cycle(0)
    
  
    
if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    asyncio.create_task(run(0,0))
    asyncio.create_task(run(17,1))
    asyncio.create_task(run(18,2))
    loop.run_forever()