button switches led speed

button_led_speed.py

@@ -0,0 +1,34 @@
+#!/usr/bin/python
+
+from time import sleep
+
+import RPi.GPIO as GPIO
+
+try:
+    GPIO.setmode(GPIO.BCM)
+    GPIO.setup(4, GPIO.OUT)
+    GPIO.setup(14, GPIO.IN, pull_up_down=GPIO.PUD_UP)
+
+    speeds = [1000, 500, 250, 150, 100, 50]
+
+    currentSpeedIndex = 0
+    msPassed = 0
+    ledOn = False
+    cycleMs = 50
+
+    while True:
+        if msPassed >= speeds[currentSpeedIndex]:
+            ledOn = ~ledOn
+            msPassed = 0
+            GPIO.output(4, ledOn)
+        buttonPressed = GPIO.input(14) == 0
+        if buttonPressed == True:
+            print 'Button pressed'
+            currentSpeedIndex = (currentSpeedIndex + 1) % len(speeds)
+            print 'New speed: ' + str(speeds[currentSpeedIndex]) + 'ms'
+        sleep(cycleMs / 1000.0)
+        msPassed += cycleMs
+except KeyboardInterrupt:
+    GPIO.output(4, False)
+finally:
+    GPIO.cleanup()