INA226.cpp

00001 /**
00002  * @section LICENSE
00003  * Released under the MIT License: http://mbed.org/license/mit
00004  * Copyright (C) 2012 tosihisa
00005  *
00006  * @section DESCRIPTION
00007  * INA226 - Bi-Directional CURRENT/POWER MONITOR with I2C
00008  * http://strawberry-linux.com/catalog/items?code=12031
00009  *
00010  */
00011 #include "mbed.h"
00012 #include "INA226.hpp"
00013 
00014 INA226::INA226(I2C &i2c_,int addr_,int freq_) : i2c(i2c_),i2c_addr(addr_),freq(freq_)
00015 {
00016     i2c.frequency(freq);
00017 }
00018 
00019 int INA226::isExist(void)
00020 {
00021     char p_addr = 0;   //Select Configuration Register.
00022     i2c.frequency(freq);
00023     if(i2c.write(i2c_addr | 0,&p_addr,sizeof(p_addr)) == 0){
00024         return 1;
00025     }
00026     return 0;
00027 }
00028 
00029 int INA226::rawWrite(char pointer_addr,unsigned short val_)
00030 {
00031     char val[3];
00032     val[0] = pointer_addr;
00033     val[1] = static_cast<char>((val_ >> 8) & 0x00ff);
00034     val[2] = static_cast<char>(val_ & 0x00ff);
00035     i2c.frequency(freq);
00036     if(i2c.write(i2c_addr | 0,val,sizeof(val)) == 0){
00037         return 0;
00038     }
00039     return 1;
00040 }
00041  
00042 int INA226::rawRead(char pointer_addr,unsigned short *val_)
00043 {
00044     char p_addr = pointer_addr;
00045     char val[2];
00046     i2c.frequency(freq);
00047     if(i2c.write(i2c_addr | 0,&p_addr,sizeof(p_addr)) == 0){
00048         if(i2c.read(i2c_addr | 0x01,val,sizeof(val)) == 0){
00049             *val_ = static_cast<unsigned short>(val[0]);
00050             *val_ = (*val_ << 8) | static_cast<unsigned short>(val[1]);
00051             return 0;
00052         }
00053     }
00054     return 1;
00055 }
00056 
00057 int INA226::getVoltage(double *V_)
00058 {
00059     unsigned short val;
00060     if(rawRead(0x02,&val) == 0){
00061         *V_ = static_cast<double>(val) * 1.25;
00062         return 0;
00063     }
00064     return 1;
00065 }
00066 
00067 int INA226::getCurrent(double *I_)
00068 {
00069     unsigned short val;
00070     if(rawRead(0x04,&val) == 0){
00071         char *s_p = reinterpret_cast<char *>(&val);
00072         short d_s;
00073         char *d_p = reinterpret_cast<char *>(&d_s);
00074         *(d_p + 0) = *(s_p + 0);
00075         *(d_p + 1) = *(s_p + 1);
00076         *I_ = static_cast<double>(d_s) /* * 1.25 */;
00077         return 0;
00078     }
00079     return 1;
00080 }
00081 
00082 int INA226::setCurrentCalibration(unsigned short val)
00083 {
00084     return rawWrite(0x05,val);
00085 }