going for v0.3.0

Author: trevorwslee

experiments/picopio/pio_neo_blink.py

@@ -0,0 +1,66 @@
+# https://docs.micropython.org/en/latest/library/rp2.html
+
+import time
+import rp2
+from machine import Pin
+
+@rp2.asm_pio(set_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT)
+def neo_prog():
+    pull()                       # osr <= number of pixels - 1
+    mov(y, osr)                  # y <= number of pixels - 1
+    label("loop_pixel")
+    mov(isr, y)                  # isr (pixel counter) <= y
+    pull()                       # sor <= 24 bits GRB
+    set(x, 23)                   # x (bit counter) <= 23
+    label("loop_pixel_bit")
+    out(y, 1)                    # y <= left-most 1 bit of sor
+    jmp(not_y, "bit_0")
+    set(pins, 1).delay(15)
+    set(pins, 0).delay(8)
+    jmp("bit_end")
+    label("bit_0")
+    set(pins, 1).delay(7)
+    set(pins, 0).delay(16)
+    label("bit_end")
+    jmp(x_dec, "loop_pixel_bit") # x is bit counter
+    mov(y, isr)                  # y <= isr (pixel counter)
+    jmp(y_dec, "loop_pixel")     # y is pixel counter
+    label("debug")
+    set(y, 8)
+    label("debug_2")
+    mov(isr, y)
+    push()
+
+sm = rp2.StateMachine(0, neo_prog, freq=20_000_000, set_base=Pin(22))
+sm.active(1)
+
+def ShowNeoPixels(*pixels):
+    '''
+    each pixel RGB is the tuple (r, g, b)
+    '''
+    pixel_count = len(pixels)
+    sm.put(pixel_count - 1)
+    for i in range(pixel_count):
+        pixel = pixels[i]
+        if pixel:
+            (r, g, b) = pixel
+        else:
+            (r, g, b) = (0, 0, 0)
+        grb = (g << 16) + (r << 8) + b  # the order is G R B
+        #print(f". [{i}] = {pixel} ({grb})")
+        sm.put(grb, 8)
+    time.sleep_us(300)
+    res = sm.get()
+    print(f"got result {res}")
+    
+NUM_PIXELS = 4
+Pixels = []
+for i in range(NUM_PIXELS):
+    Pixels.append(None)
+
+Pixels[0] = (128, 0, 0)
+Pixels[1] = (0, 128, 0)
+Pixels[2] = (0, 0, 128)
+Pixels[3] = (32, 32, 32)
+ShowNeoPixels(*Pixels)    
+