Add example 'Dimmer' for LinuxWochen Linz workshop

Dimmer/Dimmer.ino

+/* Dimmer.ino
+ *
+ * Copyright 2015 Roland Richter
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// Der analoge Eingangs-Pin des Sensors
+const int QRDPin = A0;
+
+// Der Ausgangs-Pin der LED
+const int LEDPin = 11;
+
+
+void setup()
+{
+    pinMode(QRDPin, INPUT);
+    pinMode(LEDPin, OUTPUT);
+}
+
+
+void loop()
+{
+    // Lies analogen Wert im Bereich [0,1023] ein, verwandle diesen in einen
+    // Wert im Bereich [0,255], und gib diesen Wert aus.
+    int value = analogRead(QRDPin);
+    int out = map(value, 0, 1024, 0, 255);
+    int pwm = constrain(out, 0, 255);
+
+    analogWrite(LEDPin, pwm);
+
+    delay(100);
+}
+
+/* IDEEN:
+   1. An welche Pins kann eine "dimmbare" LED angeschlossen werden, und an
+      welche nicht? Warum?
+*/