ina219_drv.h

/*
 * ina219_drv.h
 *
 *  Created on: Jun 8, 2018
 *      Author: Philipp Dressen
 *
 *  Based on: http://www.ti.com/lit/ds/symlink/ina219.pdf
 */
 
#ifndef SRC_DRIVER_INA219_DRV_H_
#define SRC_DRIVER_INA219_DRV_H_
 
#include "i2c_interface.h"
 
namespace INA219 {
    // adafruit: 0x40, 0x41, 0x44, 0x45
    static const uint8_t ADDRESS        = 0x40;
    static const uint16_t OVERFLOW        = 0xFFFF;
 
    // 16-Bit registers, MSB-First
    static const uint8_t REG_CONF       = 0x00;
    static const uint8_t REG_SHUNT_V    = 0x01;
    static const uint8_t REG_BUS_V      = 0x02;
    static const uint8_t REG_POWER      = 0x03;
    static const uint8_t REG_CURRENT    = 0x04;
    static const uint8_t REG_CAL        = 0x05;
 
    // Reset (bit 15)
    // unused (bit 14)
 
    // Bus Voltage Range (bit 13)
    enum BG : uint8_t {
        FSR16V  = 0,
        FSR32V  = 1
    };
 
    // Shunt Voltage Range (bit 12-11)
    enum PG : uint8_t {
        X1      = 0b00,    // 40mV
        X2      = 0b01,    // 80mV
        X4      = 0b10,    // 160mV
        X8      = 0b11     // 320mV
    };
 
    // Bus Voltage ADC (bit 10-7)
    // Shunt Voltage ADC (bit 6-3)
    // Resolution/Samples
    enum ADC : uint8_t {
        ADC9        = 0b0000,
        ADC10       = 0b0001,
        ADC11       = 0b0010,
        ADC12       = 0b0011,
        SAMPLES2    = 0b1001,
        SAMPLES4    = 0b1010,
        SAMPLES8    = 0b1011,
        SAMPLES16   = 0b1100,
        SAMPLES32   = 0b1101,
        SAMPLES64   = 0b1110,
        SAMPLES128  = 0b1111
    };
 
    // Mode (bit 2-0)
    enum MODE : uint8_t {
        SLEEP       = 0b000,
        TRIG_SHUNT  = 0b001,
        TRIG_BUS    = 0b001,
        TRIG        = 0b011,
        ADC_OFF     = 0b100,
        CONT_SHUNT  = 0b101,
        CONT_BUS    = 0b110,
        CONT        = 0b111
    };
}
 
class ina219_drv {
 
public:
    ina219_drv(i2c_interface & i2c, uint8_t _i2c_addr = INA219::ADDRESS);
 
    void setConfig(bool reset, INA219::BG busgain, INA219::PG powergain, INA219::ADC busadc, INA219::ADC shuntadc, INA219::MODE mode);
    void setCalibration(unsigned int maxCurrent = 3200, float shuntR = 0.1);
    float getShuntVoltage();    // mV
    float getBusVoltage();      // V
    float getCurrent();         // ma
 
private:
    i2c_interface & _i2c;
    uint8_t _i2c_addr;
 
    INA219::BG busgain      = INA219::BG::FSR32V;
    INA219::PG shuntgain    = INA219::PG::X8;
    INA219::ADC busadc      = INA219::ADC::ADC12;
    INA219::ADC shuntadc    = INA219::ADC::ADC12;
    INA219::MODE mode       = INA219::MODE::CONT;
 
    uint16_t calibration    = 0;
    float currentLSB        = 0;
 
    void writeRegister(uint8_t reg, uint16_t val);
    uint16_t readRegister(uint8_t reg);
};
 
#endif