build/shared/dist/examples/Analog/Smoothing/Smoothing.pde

@@ -1,43 +1,64 @@
 /*
- * Smoothing
- * David A. Mellis <dam@mellis.org>
- *
- * Reads repeatedly from an analog input, calculating a running average
- * and printing it to the computer. 
- *
- * http://www.arduino.cc/en/Tutorial/Smoothing
- */
+
+  Smoothing
+
+  Reads repeatedly from an analog input, calculating a running average
+  and printing it to the computer.  Keeps ten readings in an array and 
+  continually averages them.
+  
+  The circuit:
+    * Analog sensor (potentiometer will do) attached to analog input 0
+
+  Created 22 April 2007
+  By David A. Mellis  <dam@mellis.org>
+
+  http://www.arduino.cc/en/Tutorial/Smoothing
+
+
+*/
+
 
 // Define the number of samples to keep track of.  The higher the number,
 // the more the readings will be smoothed, but the slower the output will
-// respond to the input.  Using a #define rather than a normal variable lets
+// respond to the input.  Using a constant rather than a normal variable lets
 // use this value to determine the size of the readings array.
-#define NUMREADINGS 10
+const int numReadings = 10;
 
-int readings[NUMREADINGS];                // the readings from the analog input
-int index = 0;                            // the index of the current reading
-int total = 0;                            // the running total
-int average = 0;                          // the average
+int readings[numReadings];      // the readings from the analog input
+int index = 0;                  // the index of the current reading
+int total = 0;                  // the running total
+int average = 0;                // the average
 
 int inputPin = 0;
 
 void setup()
 {
-  Serial.begin(9600);                     // initialize serial communication with computer
-  for (int i = 0; i < NUMREADINGS; i++)
-    readings[i] = 0;                      // initialize all the readings to 0
+  // initialize serial communication with computer:
+  Serial.begin(9600);                   
+  // initialize all the readings to 0: 
+  for (int thisReading = 0; thisReading < numReadings; thisReading++)
+    readings[thisReading] = 0;          
 }
 
-void loop()
-{
-  total -= readings[index];               // subtract the last reading
-  readings[index] = analogRead(inputPin); // read from the sensor
-  total += readings[index];               // add the reading to the total
-  index = (index + 1);                    // advance to the next index
-  
-  if (index >= NUMREADINGS)               // if we're at the end of the array...
-    index = 0;                            // ...wrap around to the beginning
-  
-  average = total / NUMREADINGS;          // calculate the average
-  Serial.println(average);                // send it to the computer (as ASCII digits)
+void loop() {
+  // subtract the last reading:
+  total= total - readings[index];         
+  // read from the sensor:  
+  readings[index] = analogRead(inputPin); 
+  // add the reading to the total:
+  total= total + readings[index];       
+  // advance to the next position in the array:  
+  index = index + 1;                    
+
+  // if we're at the end of the array...
+  if (index >= numReadings)              
+    // ...wrap around to the beginning: 
+    index = 0;                           
+
+  // calculate the average:
+  average = total / numReadings;         
+  // send it to the computer (as ASCII digits) 
+  Serial.println(average, DEC);               
 }
+
+