Examples: adding 'main.py' for shipping firmware

Author: thirdr

examples/main.py

@@ -0,0 +1,113 @@
+import time
+
+import urequests
+from ezwifi import connect
+from machine import Pin
+
+import plasma
+
+"""
+This Plasma Stick example sets your LED strip to the current #cheerlights colour.
+Find out more about the Cheerlights API at https://cheerlights.com/
+"""
+
+URL = 'http://api.thingspeak.com/channels/1417/field/2/last.json'
+UPDATE_INTERVAL = 120  # refresh interval in secs. Be nice to free APIs!
+
+# Set how many LEDs you have
+NUM_LEDS = 50
+
+# Set the brightness
+BRIGHTNESS = 0.5
+
+
+# if no wifi connection, you get spooky rainbows. Bwahahaha!
+def wifi_failed(message=""):
+    print(f'Wifi connection failed! {message}')
+    spooky_rainbows()
+
+
+# Print out WiFi connection messages for debugging
+def wifi_message(wifi, message):
+    print(message)
+
+
+def spooky_rainbows():
+    print('SPOOKY RAINBOWS!')
+    HUE_START = 30  # orange
+    HUE_END = 140  # green
+    SPEED = 0.3  # bigger = faster (harder, stronger)
+
+    distance = 0.0
+    direction = SPEED
+    while True:
+        for i in range(NUM_LEDS):
+            # generate a triangle wave that moves up and down the LEDs
+            j = max(0, 1 - abs(distance - i) / (NUM_LEDS / 3))
+            hue = HUE_START + j * (HUE_END - HUE_START)
+
+            led_strip.set_hsv(i, hue / 360, 1.0, BRIGHTNESS)
+
+        # reverse direction at the end of colour segment to avoid an abrupt change
+        distance += direction
+        if distance > NUM_LEDS:
+            direction = - SPEED
+        if distance < 0:
+            direction = SPEED
+
+        time.sleep(0.01)
+
+
+def hex_to_rgb(hex):
+    # converts a hex colour code into RGB
+    h = hex.lstrip('#')
+    r, g, b = (int(h[i:i + 2], 16) for i in (0, 2, 4))
+    return r, g, b
+
+
+# set up the Pico W's onboard LED
+pico_led = Pin('LED', Pin.OUT)
+
+# set up the WS2812 / NeoPixel™ LEDs
+led_strip = plasma.WS2812(NUM_LEDS, color_order=plasma.COLOR_ORDER_RGB)
+
+# start updating the LED strip
+led_strip.start()
+
+# set up wifi
+try:
+    connect(failed=wifi_failed, info=wifi_message, warning=wifi_message, error=wifi_message)
+except ValueError as e:
+    wifi_failed(e)
+
+while True:
+    # open the json file
+    print(f'Requesting URL: {URL}')
+    r = urequests.get(URL)
+    # open the json data
+    j = r.json()
+    print('Data obtained!')
+    r.close()
+
+    # flash the onboard LED after getting data
+    pico_led.value(True)
+    time.sleep(0.2)
+    pico_led.value(False)
+
+    # extract hex colour from the data
+    hex = j['field2']
+
+    # and convert it to RGB
+    r, g, b = hex_to_rgb(hex)
+
+    # adjust the brightness
+    r, g, b = (int(i * BRIGHTNESS) for i in (r, g, b))
+
+    # light up the LEDs
+    for i in range(NUM_LEDS):
+        led_strip.set_rgb(i, r, g, b)
+    print(f'LEDs set to {hex}')
+
+    # sleep
+    print(f'Sleeping for {UPDATE_INTERVAL} seconds.')
+    time.sleep(UPDATE_INTERVAL)