ws2812/dma_ws2812.py

115 lines
3.3 KiB
Python

# Example using PIO to drive a set of WS2812 LEDs.
import array, time
from machine import Pin
import rp2
from time import sleep
import dma
# 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_RIGHT, 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, state_machine):
# Create the StateMachine with the ws2812 program, outputting on pin
self.sm = rp2.StateMachine(state_machine, 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
self.pio_dma = dma.PIO_DMA_Transfer(state_machine+4, state_machine, 32, num_leds)
def show(self):
#self.sm.put(self.ar)
self.pio_dma.start_transfer(self.ar)
def set(self, i, color):
self.ar[i] = int((color[1]<<16)*self.brightness) + int((color[0]<<8)*self.brightness) + int(color[2]*self.brightness)
def fill(self, color):
for i in range(len(self.ar)):
self.set(i, color)
def wait(self):
return self.pio_dma.busy()
def color_chase(self, color, wait):
for i in range(self.num_leds):
self.set(i, color)
time.sleep(wait)
self.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.num_leds):
rc_index = (i * 256 // self.num_leds) + j
self.set(i, self.wheel(rc_index & 255))
self.show()
time.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)
if __name__ == "__main__":
ws0 = WS2812B(256, 1, 1, 1)
ws1 = WS2812B(256, 2, 1, 5)
ws2 = WS2812B(256, 3, 1, 6)
while True:
for color in ws0.COLORS:
ws0.fill(color)
ws0.show()
ws1.fill(color)
ws1.show()
ws2.fill(color)
ws2.show()
time.sleep(1)