worldclock: improve performance, add intensity scaling.

Now does ~25 FPS when transitioning.  Fades based on intensity instead
of PWM level.

hw/asynced.py

@@ -7,8 +7,9 @@ def delay(secs: float) -> generator:
         yield None
 
 
-def fps(dt: float) -> generator:
+def fps(fps: float) -> generator:
     yield None
+    dt = 1 / fps
     until = time.monotonic() + dt
     while True:
         remain = until - time.monotonic()
@@ -21,6 +22,16 @@ def fps(dt: float) -> generator:
         yield None
 
 
+def wait(stop: int) -> generator:
+    start = time.monotonic()
+    while True:
+        elapsed = int((time.monotonic() - start) * 1000)
+        elapsed = min(stop, elapsed)
+        yield elapsed
+        if elapsed >= stop:
+            break
+
+
 def test():
     for f in delay(2.0):
         print(utime.ticks_ms())

hw/wordclock.py

@@ -1,11 +1,14 @@
+import array
+import random
 import time
 
 import asynced
 import iptime
-import machine
+
+from neopixel_write import neopixel_write
 import board
+import machine
 import neopixel
-import random
 
 RANGES = {
     'dude': 0,
@@ -40,6 +43,13 @@ RANGES = {
     'its': 99,
 }
 
+CIEL8 = (0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 6, 6, 7, 8, 8, 9,
+         10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 25, 26, 28,
+         30, 31, 33, 35, 37, 39, 40, 42, 44, 46, 49, 51, 53, 55, 57, 60, 63,
+         66, 68, 71, 74, 77, 80, 83, 86, 90, 93, 96, 100, 103, 107, 111, 115,
+         118, 122, 127, 131, 136, 140, 144, 149, 153, 158, 163, 168, 173, 179,
+         184, 189, 195, 200, 206, 212, 218, 224, 230, 236, 242, 249, 255)
+
 MINUTES = ('oclock', 'FIVE past', 'TEN past', 'QUARTER past', 'TWENTY past',
            'TWENTYFIVE past', 'HALF past', 'TWENTYFIVE to', 'TWENTY to',
            'QUARTER to', 'TEN to', 'FIVE to')
@@ -72,10 +82,11 @@ def to_rgb(i, colour) -> tuple:
 
 class Frame:
     Max = 255
+    Zeros = tuple([0] * (11 * 10))
 
     def __init__(self, n: int = 11 * 10, pixels: list = None):
         if pixels is None:
-            pixels = [0] * n
+            pixels = list(self.Zeros)
         self.pixels = pixels
 
     def set(self, idx: int) -> Frame:
@@ -91,6 +102,20 @@ class Frame:
         return Frame(pixels=[x * num // den for x in self.pixels])
 
 
+@micropython.native
+def merge(f1: Frame, f2: Frame, num1: int, num2: int, den: int) -> Frame:
+    m = Frame.Max
+    p1 = f1.pixels
+    p2 = f2.pixels
+    o = array.array('H', Frame.Zeros)
+    for i in range(len(p1)):
+        k = (p1[i] * num1 + p2[i] * num2) // den
+        if k >= m:
+            k = m
+        o[i] = k
+    return Frame(pixels=o)
+
+
 def render(words: list) -> Frame:
     f = Frame()
     for word in words:
@@ -109,12 +134,17 @@ def prefix() -> tuple:
 
 
 def show(f: Frame, n):
-    for i, p in enumerate(f.pixels):
-        n[i] = to_rgb(p, COLOUR)
-    n.show()
+    p = f.pixels
+    buf = bytearray(len(p) * 3)
+    r, g, b = COLOUR
+    i = 0
 
-
-DT = 0.1
+    for c in p:
+        buf[i + 1] = (r * c) >> 8
+        buf[i + 0] = (g * c) >> 8
+        buf[i + 2] = (b * c) >> 8
+        i += 3
+    neopixel_write(n.pin, buf)
 
 
 def scan() -> generator:
@@ -125,9 +155,16 @@ def scan() -> generator:
             f = f.muldiv(80, 100)
 
 
+def intensity(num: int, den: int) -> int:
+    idx = num * len(CIEL8) // den
+    if idx >= len(CIEL8):
+        return 255
+    return CIEL8[idx]
+
+
 def run() -> generator:
     words = None
-    steps = int(2.0 / DT)
+    fade = 2000
     secs = iptime.day_sec()
 
     # Flash until time is synced.
@@ -146,8 +183,9 @@ def run() -> generator:
             yield from asynced.delay(1)
             continue
         dest = render(prefix() + nxt)
-        for i in range(steps):
-            yield src.muldiv(steps - i, steps) + dest.muldiv(i, steps)
+        for at in asynced.wait(fade):
+            yield merge(src, dest, intensity(fade - at, fade),
+                        intensity(at, fade), 255)
         words = nxt
         src = dest
 
@@ -163,29 +201,19 @@ def blink() -> generator:
 
 def bench() -> generator:
     yield None
-    i = 10
+    i = 30
     while True:
         start = time.monotonic()
         yield from range(i)
         elapsed = time.monotonic() - start
-        print('%d in %.3f %.3f/1' % (i, elapsed, elapsed / i))
-
-
-def test():
-    time.sleep(1)
-    num = 11 * 10
-    n = neopixel.NeoPixel(board.GPIO2, num, brightness=0.4, auto_write=False)
-    while True:
-        for words in ITS:
-            f = render([words])
-            show(f, n)
-            time.sleep(1)
+        print('%d in %.3f %.3f/1 %.1f FPS' % (i, elapsed, elapsed / i,
+                                              i / elapsed))
 
 
 def main():
     num = 11 * 10
     n = neopixel.NeoPixel(board.GPIO2, num, brightness=1, auto_write=False)
-    routines = (run(), blink(), asynced.fps(DT), bench())
+    routines = (run(), blink(), asynced.fps(30), bench())
     while True:
         for r in routines:
             f = next(r)