added SoftPot example

Author: tigoe

SoftPot/SoftPot.ino

@@ -0,0 +1,41 @@
+/*
+  Soft pot sensor reading
+
+  Reads a SoftPot and uses the peak touch for each time you touch
+  to set an LED's brightness.
+
+  The softpot has a pulldown resistor on the wiper
+  per this SparkFun tutorial:
+  https://learn.sparkfun.com/tutorials/sik-experiment-guide-for-arduino---v32/experiment-10-reading-a-soft-potentiometer
+  The pulldown resistor ensures that the pot returns
+  a low value when not touched
+
+  created 30 Jan 2017
+  by Tom Igoe
+
+*/
+
+int lastReading = 0;    // last sensor reading
+int threshold = 10;     // touch threshold
+int brightness = 0;     // LED brightness
+int peak = 0;           // touch peak
+
+void setup() {
+  Serial.begin(9600);   // initialize serial
+  pinMode(11, OUTPUT);  // make the LED pin an output
+}
+
+void loop() {
+  int sensor = analogRead(A0);   // read sensor
+  if (sensor > threshold) {      // if it's above touch threshold
+    if (sensor > lastReading) {  // and it's above last reading
+      peak = sensor;             // then it's a peak
+    } else {                     // otherwise,
+      peak = lastReading;        // last reading is a peak
+    }
+    brightness = peak / 4;       // brightness is based on peak
+    analogWrite(11, brightness); // set LED
+    Serial.println(brightness);  // print brightness
+  }
+  lastReading = sensor;          // save current reading for next time
+}