Switch to DMA

ws2812.py

@@ -1,17 +1,11 @@
-# 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
+import dma
 
-# Configure the number of WS2812 LEDs.
+@rp2.asm_pio(sideset_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT, autopull=True, pull_thresh=8)
-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
@@ -26,58 +20,29 @@ def ws2812():
     wrap()
 
 class WS2812B: 
-    def __init__(self, num_leds, pin_num, brightness, sm):
+    def __init__(self, num_leds, pin, state_machine, brightness=0.1, invert=False):
-        # 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))
-        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)
-
+        self.ar = bytearray(num_leds*3)
-        # 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.invert = invert
+        self.pio_dma = dma.PIO_DMA_Transfer(state_machine+4, state_machine, 8, num_leds*3)
 
-    ##########################################################################
+    def show(self):
-    async def pixels_show(self):
+        self.pio_dma.start_transfer(self.ar)
-        self.sm.put(self.ar, 8)
-        await asyncio.sleep(0.00001)
         
-    def pixels_set(self, i, color):
+    def set(self, i, color):
-        self.ar[i] = (int(color[1]*self.brightness)<<16) + (int(color[0]*self.brightness)<<8) + int(color[2]*self.brightness)
+        self.ar[i*3] = int(color[1]*self.brightness)
+        self.ar[i*3+1] = int(color[0]*self.brightness)
+        self.ar[i*3+2] = int(color[2]*self.brightness)
     
-    def pixels_fill(self, color):
+    def 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)
+            self.set(i, color)
-            await asyncio.sleep(wait)
-            await self.pixels_show()
-        await asyncio.sleep(0.2)
 
-    def wheel(self, pos):
+    def busy(self):
-        # Input a value 0 to 255 to get a color value.
+        return self.pio_dma.busy()
-        # 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)
@@ -89,21 +54,14 @@ class WS2812B:
     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()
+    num_leds, pin, sm, brightness = 10, 0, 0, 1
-    asyncio.create_task(run(0,0))
+    ws0 = WS2812B(num_leds, pin, sm, brightness)
-    asyncio.create_task(run(17,1))
+    while True:
-    asyncio.create_task(run(18,2))
+        for color in ws0.COLORS:
-    loop.run_forever()
+            ws0.fill(color)
+            ws0.show()
+            time.sleep(1)