ACS712.cpp

00001 #include "ACS712.h"
00002 #include "mbed.h"
00003 
00004 // Constructor/Destructor
00005 ACS712::ACS712(PinName const outpin) 
00006     
00007     : 
00008     
00009     _aInPin(new AnalogIn(outpin))
00010     
00011 {}
00012 
00013 ACS712::~ACS712()
00014 {
00015     delete _aInPin;
00016 }
00017 
00018 // ----- Public Methods -----
00019 
00020 void ACS712::init() 
00021 {
00022 
00023 }
00024 double ACS712::read_current_sensor()
00025 {    
00026     double val;
00027     val = _aInPin->read();
00028     val *= val;
00029     val = sqrt(val);
00030     return val;
00031 }
00032 
00033 int ACS712::read_ain_uint_16()
00034 {
00035     int val = 0;
00036     
00037     val = _aInPin->read_u16();
00038     
00039     return val;
00040 }
00041 
00042 void ACS712::convert_to_amps(float acs_offset, float gain, int type)
00043 {   
00044     
00045     double _current_in = read_current_sensor()*3.3;
00046     
00047     switch(type) {
00048         
00049         case 5:
00050         _current = (acs_offset*gain - _current_in*gain)/.185*gain;    
00051         break;
00052         case 20:
00053         _current = (acs_offset*gain - _current_in*gain)/.100*gain;    
00054         break;
00055         case 30:
00056         _current = (_current_in*gain - acs_offset*gain)/.066*gain; 
00057         break;
00058         default:
00059         _current = 999.9;
00060         break;
00061         
00062         }
00063     
00064 }
00065 
00066 
00067 bool ACS712::over_current_detection(double operating_current)
00068 {    
00069 
00070     bool current_spike_flag = false;
00071     
00072     if(_current > (1.1*operating_current)) {
00073         
00074         current_spike_flag = true;
00075         
00076         }
00077     else {
00078         
00079         current_spike_flag = false;
00080         
00081         }
00082     
00083     return current_spike_flag;
00084 
00085 }
00086 
00087 float ACS712::get_current_amps()    
00088 {
00089     
00090     return _current;
00091     
00092 }