Merge pull request #65 from dcbriccetti/accel-maps-pixels

Create an acceleration to LEDs example

examples/circuitplayground_acceleration_mapping_neopixels.py

@@ -0,0 +1,48 @@
+"""Maps acceleration (tilt) to Neopixel colors.
+
+x, y, and z acceleration components map to red, green and blue,
+respectively.
+
+When the CPX is level, the lights are blue because there is no acceleration
+on x or y, but on z, gravity pulls at 9.81 meters per second per second (m/s²).
+When banking, the vertical (z) axis is no longer directly aligned with gravity,
+so the blue decreases, and red increases because gravity is now pulling more
+along the x axis. Similarly, when changing the pitch from level, we see blue change
+to green.
+
+This video walks you through the code: https://youtu.be/eNpPLbYx-iA
+"""
+
+import time
+from adafruit_circuitplayground.express import cpx
+
+cpx.pixels.brightness = 0.2  # Adjust overall brightness as desired, between 0 and 1
+
+
+def color_amount(accel_component):
+    """Convert acceleration component (x, y, or z) to color amount (r, g, or b)"""
+    standard_gravity = 9.81  # Acceleration (m/s²) due to gravity at the earth’s surface
+    accel_magnitude = abs(accel_component)                      # Ignore the direction
+    constrained_accel = min(accel_magnitude, standard_gravity)  # Constrain values
+    normalized_accel = constrained_accel / standard_gravity     # Convert to 0–1
+    return round(normalized_accel * 255)                        # Convert to 0–255
+
+
+def format_acceleration():
+    return ', '.join(('{:>6.2f}'.format(axis_value) for axis_value in acceleration))
+
+
+def format_rgb():
+    return ', '.join(('{:>3d}'.format(rgb_amount) for rgb_amount in rgb_amounts))
+
+
+def log_values():
+    print('({}) ==> ({})'.format(format_acceleration(), format_rgb()))
+
+
+while True:
+    acceleration = cpx.acceleration
+    rgb_amounts = [color_amount(axis_value) for axis_value in acceleration]
+    cpx.pixels.fill(rgb_amounts)
+    log_values()
+    time.sleep(0.1)

examples/circuitplayground_acceleration_neopixels.py

@@ -18,10 +18,4 @@ while True:
         B = 0
         x, y, z = cpx.acceleration
         print((x, y, z))
-        if x:
+        cpx.pixels.fill(((R + abs(int(x))), (G + abs(int(y))), (B + abs(int(z)))))
-            R = R + abs(int(x))
-        if y:
-            G = G + abs(int(y))
-        if z:
-            B = B + abs(int(z))
-        cpx.pixels.fill((R, G, B))