Add EyeLights Googly Rings, rename Accelerometer Rings to disambiguate

EyeLights_Googly_Rings/code.py

@@ -0,0 +1,107 @@
+"""
+GOOGLY EYES for Adafruit EyeLight LED glasses + driver. Pendulum physics
+simulation using accelerometer and math. This uses only the rings, not the
+matrix portion. Adapted from Bill Earl's STEAM-Punk Goggles project:
+https://learn.adafruit.com/steam-punk-goggles
+"""
+
+import math
+import random
+import board
+import supervisor
+import adafruit_lis3dh
+import adafruit_is31fl3741
+from adafruit_is31fl3741.adafruit_ledglasses import LED_Glasses
+
+
+# HARDWARE SETUP ----
+
+i2c = board.I2C()  # Shared by both the accelerometer and LED controller
+
+# Initialize the accelerometer
+lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c)
+
+# Initialize the IS31 LED driver, buffered for smoother animation
+glasses = LED_Glasses(i2c, allocate=adafruit_is31fl3741.MUST_BUFFER)
+
+
+# PHYSICS SETUP -----
+
+
+class Pendulum:
+    """A small class for our pendulum simulation."""
+
+    def __init__(self, ring, color):
+        """Initial pendulum position, plus axle friction, are randomized
+        so the two rings don't spin in perfect lockstep."""
+        self.ring = ring  # Save reference to corresponding LED ring
+        self.color = color  # (R,G,B) tuple for color
+        self.angle = random.random()  # Position around ring, in radians
+        self.momentum = 0
+        self.friction = random.uniform(0.85, 0.9)  # Inverse friction, really
+
+    def interp(self, pixel, scale):
+        """Given a pixel index (0-23) and a scaling factor (0.0-1.0),
+        interpolate between LED "off" color (at 0.0) and this item's fully-
+        lit color (at 1.0) and set pixel to the result."""
+        self.ring[pixel] = (
+            (int(self.color[0] * scale) << 16)
+            | (int(self.color[1] * scale) << 8)
+            | int(self.color[2] * scale)
+        )
+
+    def iterate(self, xyz):
+        """Given an accelerometer reading, run one cycle of the pendulum
+        physics simulation and render the corresponding LED ring."""
+        # Minus here is because LED pixel indices run clockwise vs. trigwise.
+        # 0.05 is just an empirically-derived scaling fudge factor that looks
+        # good; smaller values for more sluggish rings, higher = more twitch.
+        self.momentum = (
+            self.momentum * self.friction
+            - (math.cos(self.angle) * xyz[2] + math.sin(self.angle) * xyz[0]) * 0.05
+        )
+        self.angle += self.momentum
+
+        # Scale pendulum angle into pixel space
+        midpoint = self.angle * 12 / math.pi % 24
+        # Go around the whole ring, setting each pixel based on proximity
+        # (this is also to erase the prior position)...
+        for i in range(24):
+            dist = abs(midpoint - i)  # Pixel to pendulum distance...
+            if dist > 12:  #            If it crosses the "seam" at top,
+                dist = 24 - dist  #      take the shorter path.
+            if dist > 5:  #             Not close to pendulum,
+                self.ring[i] = 0  #      erase pixel.
+            elif dist < 2:  #           Close to pendulum,
+                self.interp(i, 1.0)  #   solid color
+            else:  #                    Anything in-between,
+                self.interp(i, (5 - dist) / 3)  # interpolate
+
+
+# List of pendulum objects, of which there are two: one per glasses ring
+pendulums = [
+    Pendulum(glasses.left_ring, (0, 20, 50)),  # Cerulean blue,
+    Pendulum(glasses.right_ring, (0, 20, 50)),  # 50 is plenty bright!
+]
+
+
+# MAIN LOOP ---------
+
+while True:
+
+    # The try/except here is because VERY INFREQUENTLY the I2C bus will
+    # encounter an error when accessing either the accelerometer or the
+    # LED driver, whether from bumping around the wires or sometimes an
+    # I2C device just gets wedged. To more robustly handle the latter,
+    # the code will restart if that happens.
+    try:
+
+        accel = lis3dh.acceleration
+        for p in pendulums:
+            p.iterate(accel)
+
+        glasses.show()
+
+    # See "try" notes above regarding rare I2C errors.
+    except OSError:
+        supervisor.reload()