piezo

[sketchbook_andrea] / basic / analog_input / photo_7_tonePitchFollower / photo_7_tonePitchFollower.ino

diff --git a/basic/analog_input/photo_7_tonePitchFollower/photo_7_tonePitchFollower.ino b/basic/analog_input/photo_7_tonePitchFollower/photo_7_tonePitchFollower.ino
index e74c7b343449a5c366c457ebb127c5887d99dcc4..dcfc5b73a5326c3ce0111c73ae9c6d34cfd2d462 100644 (file)
--- a/basic/analog_input/photo_7_tonePitchFollower/photo_7_tonePitchFollower.ino
+++ b/basic/analog_input/photo_7_tonePitchFollower/photo_7_tonePitchFollower.ino
@@ -18,25 +18,55 @@ This example code is in the public domain.
  
  */
 
+// These constants won't change:
+const int sensorPin = A0;    // pin that the sensor is attached to
+const int ledPin = 9;        // pin that the LED is attached to
+
+// variables:
+int sensorValue = 0;         // the sensor value
+int sensorMin = 1023;        // minimum sensor value
+int sensorMax = 0;           // maximum sensor value
 
 void setup() {
   // initialize serial communications (for debugging only):
   Serial.begin(9600);
+    pinMode(13, OUTPUT);
+  digitalWrite(13, HIGH);
+
+  // calibrate during the first five seconds 
+  while (millis() < 5000) {
+    sensorValue = analogRead(sensorPin);
+
+    // record the maximum sensor value
+    if (sensorValue > sensorMax) {
+      sensorMax = sensorValue;
+    }
+
+    // record the minimum sensor value
+    if (sensorValue < sensorMin) {
+      sensorMin = sensorValue;
+    }
+  }
+
+  // signal the end of the calibration period
+  digitalWrite(13, LOW);
 }
 
 void loop() {
   // read the sensor:
-  int sensorReading = analogRead(A0);
+  int sensorReading = analogRead(sensorPin);
   // print the sensor reading so you know its range
   Serial.println(sensorReading);
   // map the analog input range (in this case, 400 - 1000 from the photoresistor)
   // to the output pitch range (120 - 1500Hz)
   // change the minimum and maximum input numbers below
   // depending on the range your sensor's giving:
-  int thisPitch = map(sensorReading, 400, 1000, 120, 1500);
+  int thisPitch = map(sensorReading, sensorMin, sensorMax, 220, 3500);
 
   // play the pitch:
-  tone(9, thisPitch, 10);
+  if (sensorReading < sensorMax -50) {
+  tone(ledPin, thisPitch, 10);
+  }
   delay(1);        // delay in between reads for stability
 }