more sewable led content

en/tutorials/sewable_leds.md

@@ -69,5 +69,34 @@ Your LED should light up yellow now :)
 ### Sample application
 This example queries the state of the lower right button and turns multiple RGB LEDs on when the button is pressed:
 
+You can adjust the color, number of leds and which pin is used.
+```
+import buttons
+import ws2812
+import utime
+
+COLOR_ON = color.YELLOW * 0.2 # 20% yellow
+COLOR_OFF = [0, 0, 0]
+
+LED_NUM = 2 # number of attached LEDs
+LED_PIN = gpio.WRISTBAND_1
+
+state = False
+while True:
+    if buttons.read(buttons.BOTTOM_RIGHT):
+        state = not state
+        if state:
+            color = COLOR_ON
+        else:
+            color = COLOR_OFF
+
+        ws2812.set_all(LED_PIN, [color] * LED_NUM)
+
+        # Debounce the button
+        utime.sleep(0.1)
+        while buttons.read(buttons.BOTTOM_RIGHT): pass
+        utime.sleep(0.1)
+```
+
 An example which connects the accelerometer with multiple RGB LEDs. They start lighting up when the card10 is moved: