Diff: ACS712.h

Revision:

1:f68acb38a472

Parent:

0:a35011a2fdaa

Child:

2:ac894e4cff0d

--- a/ACS712.h	Wed Mar 09 04:19:10 2016 +0000
+++ b/ACS712.h	Mon Mar 14 13:44:12 2016 +0000
@@ -1,56 +1,93 @@
 #include <mbed.h>
-
+/** A Hall-Effect sensor for measuring current levels in a given path
+ *
+ * Can be used as a current detector
+ *
+ * Example:
+ * @code
+ * // Periodically read current levels in a circuit and
+ * // send output to PC terminal
+ *
+ * #include "mbed.h"
+ * #include "ACS712.h"
+ *
+ * // Connect the sensor analog output pin to mbed's AnalogIn pin
+ * ACS712 dev(p18);
+ * // Connect mbed to pc's USB port
+ * Serial pc(USBTX, USBRX);
+ *
+ * int main() {
+ *      pc.printf("Sensor Log: \n\n\r");
+ *      while (1) {
+ *          // Read current from sensor and output to pc terminal
+ *          pc.printf("Sensor Value: %2.2f A\n\r", dev);
+ *          wait(0.200);
+ *      }
+ * }
+ * @endcode
+ */
+ 
 class ACS712 { 
     
     public:
+        /** Create a hall-effect sensor of the specified type
+         *
+         * @param _pin mbed AnalogIn pin where the analog output of sensor is connected
+         * @param voltDivRatio resistor voltage division ratio at output of the sensor
+         * @param type type of ACS712 sensor used
+         *
+         * @note Supported types of sensors:
+         */
         ACS712(PinName _pin, float voltDivRatio = 1, short type = 5);
         
+        /** Read the value of the measured current in amps
+         *
+         * @return current value in amps
+         */
         float read();
-        float operator=(ACS712&);
-        //void sampleInterval(float);
-        //void sampleFrequency(float);
-        //void bufferLength(int);
-        //float[] readBuffer();
+        ACS712& operator=(const ACS712&);
+        
+        /** Read the value of the measured current in amps
+         *  Allows the ACS712 object to be used in a float context
+         * 
+         * @return current value in amps
+         */
+        operator float() { return read(); }
         
     private:
         AnalogIn sensor;
         float translate(float);
-        //float[] circularBuffer;
-        //float interval;
         float ratio;
         short type;
 
 };
 
-ACS712::ACS712(PinName _pin, float voltDivRatio, short type) : sensor(_pin){
+ACS712::ACS712(PinName _pin, float voltDivRatio, short sensorType) : sensor(_pin){
     ratio = voltDivRatio;
-    type = type;    
+    type = sensorType;    
 }
 
 float ACS712::translate(float val){
     switch(type){
         case 5: 
-            return (val*ratio - 2.5*ratio)/(.185*ratio);
-        break;
+            return (val*ratio - 2.46*ratio)/(.185*ratio);
         case 20:
-            return (val*ratio - 2.5*ratio)/(.1*ratio);
-        break;
+            return (val*ratio - 2.46*ratio)/(.1*ratio);
         case 30:
-            return (val*ratio - 2.5*ratio)/(.066*ratio);
-        break;
+            return (val*ratio - 2.46*ratio)/(.066*ratio);
         default:
             return 999;
-        break;
-
     }
 }
 
 
 float ACS712::read(){
-    return ACS712::translate(sensor);   
+    return ACS712::translate(sensor * 3.3);   
 }
 
-float ACS712::operator=(ACS712& rhs){
-    return rhs.read();
+ACS712& ACS712::operator=(const ACS712& rhs){
+    sensor = rhs.sensor;
+    ratio = rhs.ratio;
+    type = rhs.type;
+    return *this;
 }
-