add festive examples

micropython/examples/plasma_stick/snow.py

@@ -0,0 +1,61 @@
+import plasma
+from plasma import plasma_stick
+from random import uniform
+
+"""
+Snow in a bottle! Always winter, never Christmas!
+Adjust SNOW_INTENSITY for more snow.
+"""
+
+# Set how many LEDs you have
+NUM_LEDS = 50
+
+# How much snow? [bigger number = more snowflakes] 
+SNOW_INTENSITY = 0.0002
+
+# Change RGB colours here (RGB colour picker: https://g.co/kgs/k2Egjk )
+BACKGROUND_COLOUR = [30, 50, 50]  # dim blue
+SNOW_COLOUR = [240, 255, 255]  # bluish white
+
+# how quickly current colour changes to target colour [1 - 255]
+FADE_UP_SPEED = 255  # abrupt change for a snowflake
+FADE_DOWN_SPEED = 1
+
+
+def display_current():
+    # paint our current LED colours to the strip
+    for i in range(NUM_LEDS):
+        led_strip.set_rgb(i, current_leds[i][0], current_leds[i][1], current_leds[i][2])
+
+def move_to_target():
+    # nudge our current colours closer to the target colours
+    for i in range(NUM_LEDS):
+        for c in range(3):  # 3 times, for R, G & B channels
+            if current_leds[i][c] < target_leds[i][c]:
+                current_leds[i][c] = min(current_leds[i][c] + FADE_UP_SPEED, target_leds[i][c])  # increase current, up to a maximum of target
+            elif current_leds[i][c] > target_leds[i][c]:
+                current_leds[i][c] = max(current_leds[i][c] - FADE_DOWN_SPEED, target_leds[i][c])  # reduce current, down to a minimum of target
+
+
+# Create a list of [r, g, b] values that will hold current LED colours, for display
+current_leds = [[0] * 3 for i in range(NUM_LEDS)]
+# Create a list of [r, g, b] values that will hold target LED colours, to move towards
+target_leds = [[0] * 3 for i in range(NUM_LEDS)]
+
+# set up the WS2812 / NeoPixel™ LEDs
+led_strip = plasma.WS2812(NUM_LEDS, 0, 0, plasma_stick.DAT, color_order=plasma.COLOR_ORDER_RGB)
+
+# start updating the LED strip
+led_strip.start()
+
+while True:
+    for i in range(NUM_LEDS):
+        # randomly add snow
+        if SNOW_INTENSITY > uniform(0, 1): 
+            # set a target to start a snowflake
+            target_leds[i] = SNOW_COLOUR
+        # slowly reset snowflake to background
+        if current_leds[i] == target_leds[i]:
+             target_leds[i] = BACKGROUND_COLOUR       
+    move_to_target()   # nudge our current colours closer to the target colours
+    display_current()  # display current colours to strip

micropython/examples/plasma_stick/sparkles.py

@@ -0,0 +1,60 @@
+import plasma
+from plasma import plasma_stick
+from random import uniform
+
+"""
+A festive sparkly effect. Play around with BACKGROUND_COLOUR and SPARKLE_COLOUR for different effects!
+"""
+
+# Set how many LEDs you have
+NUM_LEDS = 50
+
+# How many sparkles? [bigger number = more sparkles]
+SPARKLE_INTENSITY = 0.005
+
+# Change your colours here! RGB colour picker: https://g.co/kgs/k2Egjk
+BACKGROUND_COLOUR = [50, 50, 0]
+SPARKLE_COLOUR = [255, 255, 0]
+
+# how quickly current colour changes to target colour [1 - 255]
+FADE_UP_SPEED = 2
+FADE_DOWN_SPEED = 2
+
+
+def display_current():
+    # paint our current LED colours to the strip
+    for i in range(NUM_LEDS):
+        led_strip.set_rgb(i, current_leds[i][0], current_leds[i][1], current_leds[i][2])
+
+def move_to_target():
+    # nudge our current colours closer to the target colours
+    for i in range(NUM_LEDS):
+        for c in range(3):  # 3 times, for R, G & B channels
+            if current_leds[i][c] < target_leds[i][c]:
+                current_leds[i][c] = min(current_leds[i][c] + FADE_UP_SPEED, target_leds[i][c])  # increase current, up to a maximum of target
+            elif current_leds[i][c] > target_leds[i][c]:
+                current_leds[i][c] = max(current_leds[i][c] - FADE_DOWN_SPEED, target_leds[i][c])  # reduce current, down to a minimum of target
+
+
+# Create a list of [r, g, b] values that will hold current LED colours, for display
+current_leds = [[0] * 3 for i in range(NUM_LEDS)]
+# Create a list of [r, g, b] values that will hold target LED colours, to move towards
+target_leds = [[0] * 3 for i in range(NUM_LEDS)]
+
+# set up the WS2812 / NeoPixel™ LEDs
+led_strip = plasma.WS2812(NUM_LEDS, 0, 0, plasma_stick.DAT, color_order=plasma.COLOR_ORDER_RGB)
+
+# start updating the LED strip
+led_strip.start()
+
+while True:
+    for i in range(NUM_LEDS):
+        # randomly add sparkles
+        if SPARKLE_INTENSITY > uniform(0, 1): 
+            # set a target to start a sparkle
+            target_leds[i] = SPARKLE_COLOUR
+        # for any sparkles that have achieved max sparkliness, reset them to background
+        if current_leds[i] == target_leds[i]:
+             target_leds[i] = BACKGROUND_COLOUR       
+    move_to_target()   # nudge our current colours closer to the target colours
+    display_current()  # display current colours to strip

micropython/examples/plasma_stick/tree.py

@@ -0,0 +1,43 @@
+import time
+import plasma
+from plasma import plasma_stick
+from random import random, choice
+
+"""
+A Christmas tree, with fairy lights!
+This will probably work better if your LEDs are in a vaguely tree shaped bottle :)
+"""
+
+# Set how many LEDs you have
+NUM_LEDS = 50
+
+# we're using HSV colours in this example - find more at https://colorpicker.me/
+# to convert a hue that's in degrees, divide it by 360
+TREE_COLOUR = [0.34, 1.0, 0.6]
+LIGHT_RATIO = 8  # every nth pixel is a light, the rest are tree.
+LIGHT_COLOURS = ((0.0, 1.0, 1.0),  # red
+                 (0.1, 1.0, 1.0),  # orange
+                 (0.6, 1.0, 1.0),  # blue
+                 (0.85, 0.4, 1.0)) # pink
+LIGHT_CHANGE_CHANCE = 0.5  # change to 0.0 if you want static lights 
+
+# set up the WS2812 / NeoPixel™ LEDs
+led_strip = plasma.WS2812(NUM_LEDS, 0, 0, plasma_stick.DAT, color_order=plasma.COLOR_ORDER_RGB)
+
+# start updating the LED strip
+led_strip.start()
+
+#initial setup 
+for i in range(NUM_LEDS):
+    if i % LIGHT_RATIO == 0:  # add an appropriate number of lights
+        led_strip.set_hsv(i, *choice(LIGHT_COLOURS))  ## choice randomly chooses from a list
+    else:  # GREEN
+        led_strip.set_hsv(i, *TREE_COLOUR)
+        
+# animate
+while True:
+    for i in range(NUM_LEDS):
+        if (i % LIGHT_RATIO == 0) and (random() < LIGHT_CHANGE_CHANCE):
+            led_strip.set_hsv(i, *choice(LIGHT_COLOURS))
+    time.sleep(0.5)
+