Adding a few basic examples.

examples/decorators.py

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+# SPDX-FileCopyrightText: 2021 Sandy Macdonald
+#
+# SPDX-License-Identifier: MIT
+
+# This example demonstrates attaching functions to keys using decorators, and
+# the ability to turn the LEDs off with led_sleep_enabled and led_sleep_time.
+
+import time
+import board
+import random
+from keybow2040 import Keybow2040
+
+# Set up Keybow
+i2c = board.I2C()
+keybow = Keybow2040(i2c)
+keys = keybow.keys
+
+# Enable LED sleep and set a time of 5 seconds before the LEDs turn off.
+keybow.led_sleep_enabled = True
+keybow.led_sleep_time = 5
+
+# Loop through the keys and set the RGB colour for the keys to magenta.
+for key in keys:
+    key.rgb = (255, 0, 255)
+
+    # Attach a `on_hold` decorator to the key that toggles the key's LED when
+    # the key is held (the default hold time is 0.75 seconds).
+    @keybow.on_hold(key)
+    def hold_handler(key):
+        key.toggle_led()
+
+while True:
+    # Always remember to call keybow.update()!
+    keybow.update()

examples/rainbow.py

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+# SPDX-FileCopyrightText: 2021 Sandy Macdonald
+#
+# SPDX-License-Identifier: MIT
+
+# This example displays a rainbow animation on Keybow 2040's keys.
+
+import time
+import math
+import board
+from keybow2040 import Keybow2040, number_to_xy
+
+
+def hsv_to_rgb(h, s, v):
+    # Convert an HSV (0.0-1.0) colour to RGB (0-255)
+    if s == 0.0:
+        rgb = [v, v, v]
+    
+    i = int(h * 6.0)
+
+    f = (h*6.)-i; p,q,t = v*(1.-s), v*(1.-s*f), v*(1.-s*(1.-f)); i%=6
+    
+    if i == 0:
+        rgb = [v, t, p]
+    if i == 1:
+        rgb = [q, v, p]
+    if i == 2:
+        rgb = [p, v, t]
+    if i == 3:
+        rgb = [p, q, v]
+    if i == 4:
+        rgb = [t, p, v]
+    if i == 5:
+        rgb = [v, p, q]
+
+    rgb = (int(c * 255) for c in rgb)
+
+    return rgb
+
+# Set up Keybow
+i2c = board.I2C()
+keybow = Keybow2040(i2c)
+keys = keybow.keys
+
+# Increment step to shift animation across keys.
+step = 0
+
+while True:
+    # Always remember to call keybow.update() on every iteration of your loop!
+    keybow.update()
+
+    step += 1
+
+    for i in range(16):
+        # Convert the key number to an x/y coordinate to calculate the hue
+        # in a matrix style-y.
+        x, y = number_to_xy(i)
+
+        # Calculate the hue.
+        hue = (x + y + (step / 20)) / 8
+        hue = hue - int(hue)
+        hue = hue - math.floor(hue)
+
+        # Convert the hue to RGB values.
+        r, g, b = hsv_to_rgb(hue, 1, 1)
+
+        # Display it on the key!
+        keys[i].set_led(r, g, b)

examples/reactive-press.py

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+# SPDX-FileCopyrightText: 2021 Sandy Macdonald
+#
+# SPDX-License-Identifier: MIT
+
+# This example demonstrates how to light keys when pressed.
+
+import board
+from keybow2040 import Keybow2040
+
+# Set up Keybow
+i2c = board.I2C()
+keybow = Keybow2040(i2c)
+keys = keybow.keys
+
+# Use cyan as the colour.
+rgb = (0, 255, 255)
+
+while True:
+    # Always remember to call keybow.update() on every iteration of your loop!
+    keybow.update()
+
+    # Loop through the keys and set the LED to cyan if pressed, otherwise turn
+    # it off (set it to black).
+    for key in keys:
+        if key.pressed:
+            key.set_led(*rgb)
+        else:
+            key.set_led(0, 0, 0)