ACS712.cpp

00001 #include "ACS712.h"
00002 
00003 ACS712::ACS712() : sensor(SENSOR_PIN),
00004                    currentSwitch(SWITCH_PIN)
00005 {
00006     currentSwitch = 1;      //turn off the currentSwitch (1 = off, 0 = on)
00007     m = 0;
00008     b = 0;
00009 }
00010 
00011 void ACS712::calibrate(){
00012     float V1,V2,A1,A2;
00013     A1 = LOW_CURRENT;
00014     A2 = HIGH_CURRENT;
00015     
00016     currentSwitch = 1;
00017     wait_ms(100);
00018 //wait_ms(5000);//MARK
00019     V1 = read_sensor(CALIBRATION_SAMPLES,10);
00020 
00021     currentSwitch = 0;
00022     //Thread::wait(100);
00023 //wait_ms(5000);//MARK
00024     wait_ms(100);
00025     V2 = read_sensor(CALIBRATION_SAMPLES,10);
00026     currentSwitch = 1;
00027     m = (A2-A1)/(V2-V1);
00028     b = A1 - V1*m;
00029 }
00030 float ACS712::get_current(){
00031     return m*read_sensor(10,0) + b;
00032 }
00033 float ACS712::read_sensor(){
00034     sensor_val = sensor.read();
00035     return sensor_val;
00036 }
00037 float ACS712::read_sensor(int n, int t){
00038     sensor_val = 0;
00039     for(int i = 0; i<n; i++){
00040         sensor_val += sensor.read();
00041         wait_ms(t);
00042         //Thread::wait(10);
00043     }
00044     sensor_val = sensor_val/float(n);
00045     return sensor_val;
00046 }