216 lines
7.3 KiB
C++
216 lines
7.3 KiB
C++
/******************************************************************************
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* TI INA219 hi-side i2c current/power monitor Library
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*
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* http://www.ti.com/product/ina219
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*
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* 6 May 2012 by John De Cristofaro
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*
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*
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* Tested at standard i2c 100kbps signaling rate.
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*
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* This library does not handle triggered conversion modes. It uses the INA219
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* in continuous conversion mode. All reads are from continous conversions.
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*
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* A note about the gain (PGA) setting:
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* The gain of the ADC pre-amplifier is programmable in the INA219, and can
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* be set between 1/8x (default) and unity. This allows a shunt voltage
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* range of +/-320mV to +/-40mV respectively. Something to keep in mind,
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* however, is that this change in gain DOES NOT affect the resolution
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* of the ADC, which is fixed at 1uV. What it does do is increase noise
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* immunity by exploiting the integrative nature of the delta-sigma ADC.
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* For the best possible reading, you should set the gain to the range
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* of voltages that you expect to see in your particular circuit. See
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* page 15 in the datasheet for more info about the PGA.
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*
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* Known bugs:
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* * may return unreliable values if not connected to a bus or at
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* bus currents below 10uA.
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*
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* Arduino 1.0 compatible as of 6/6/2012
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*
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* Dependencies:
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* * Arduino Wire library
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*
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* MIT license
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******************************************************************************/
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#ifndef ina219_h
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#define ina219_h
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#if ARDUINO >= 100
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#include "Arduino.h"
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#else
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#include "WProgram.h"
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#endif
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#include <Wire.h>
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#define INA219_DEBUG 0
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// default values
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#define D_SHUNT 0.1
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#define D_V_BUS_MAX 32
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#define D_V_SHUNT_MAX 0.2
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#define D_I_MAX_EXPECTED 2
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class INA219
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{
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public:
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///I2C address definations.
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/// Adafruit breakout board have two jumppers to set unique
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/// address for each board ( in case there is more than one in Your system)
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/// base address is 0x40, no jumpers needed)
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enum t_i2caddr{
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I2C_ADDR_40 = 0x40, ///< address 0x40 no jumpers required.
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I2C_ADDR_41 = 0x41, ///< address 0x41 bridge A0.
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I2C_ADDR_44 = 0x44, ///< address 0x44 bridge A1.
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I2C_ADDR_45 = 0x45 ///< address 0x45 bridge A0 & A1.
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};
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///Sets PGA gain and range. Note that the PGA defaults to <20>8 (320mV range).
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///Configuration reister bits 11, 12 are used for this.
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enum t_gain{
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GAIN_1_40MV = 0,
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GAIN_2_80MV = 1,
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GAIN_4_160MV = 2,
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GAIN_8_320MV = 3
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};
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///Bus voltage range.
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///Configuration register bit 13 defines this.
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enum t_range{
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RANGE_16V = 0, ///< Range 0-16 volts
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RANGE_32V = 1 ///< Range 0-32 volts
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};
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///ADC resolution (9-, 10-, 11-, or 12-bit) or set the number of samples.
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///Same definations are used both shunt and bus adc.
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///Configuration register bits 3<>6 are used for averaging results for the Shunt Voltage Register (01h).
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///And bits 7-10 are used averaging results for the Bus Voltage Register (02h).
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/// \see t_reg
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enum t_adc{
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ADC_9BIT = 0, ///< 9bit converion time 84us.
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ADC_10BIT = 1, ///< 10bit converion time 148us.
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ADC_11BIT = 2, ///< 11bit converion time 2766us.
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ADC_12BIT = 3, ///< 12bit converion time 532us.
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ADC_2SAMP = 9, ///< 2 samples converion time 1.06ms.
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ADC_4SAMP = 10, ///< 4 samples converion time 2.13ms.
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ADC_8SAMP = 11, ///< 8 samples converion time 4.26ms.
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ADC_16SAMP = 12, ///< 16 samples converion time 8.51ms
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ADC_32SAMP = 13, ///< 32 samples converion time 17.02ms.
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ADC_64SAMP = 14, ///< 64 samples converion time 34.05ms.
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ADC_128SAMP = 15, ///< 128 samples converion time 68.10ms.
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};
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///Selects continuous, triggered, or power-down mode of operation. These bits default to continuous shunt and bus measurement mode.
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///\n Please note: <b>Thus library does not support triggered converion I have comment out values to set trigged mode</b>.\n
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///Configuration register bits 0-2 are used for this. \see t_reg
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enum t_mode{
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PWR_DOWN = 0,
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/*
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TRIG_SH = 1,
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TRIG_BUS = 2,
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TRIG_SH_BUS = 3,
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*/
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ADC_OFF = 4,
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CONT_SH = 5, ///<Shunt Continuous.
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CONT_BUS = 6, ///<Bus Continuous.
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CONT_SH_BUS = 7 ///<Shunt and Bus, Continuous.
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};
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///Constructor
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INA219( t_i2caddr addr = I2C_ADDR_40 ///< Device address.
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);
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/// Start i2 communication with actual device.
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void begin( );
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/// calibration of equations and device.
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/// default values are for a 0.25 Ohm shunt on a 5V bus with max current of 1A
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void calibrate( float r_shunt = D_SHUNT, ///< Value of shunt in Ohms.
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float v_shunt_max = D_V_SHUNT_MAX, ///< Maximum value of voltage across shunt.
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float v_bus_max = D_V_BUS_MAX, ///< Maximum voltage of bus.
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float i_max_expected = D_I_MAX_EXPECTED ///< Maximum current draw of bus + shunt.
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);
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/// Config values (range, gain, bus adc, shunt adc, mode).
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void configure( t_range range = RANGE_32V, ///< Range for bus voltage.
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t_gain gain = GAIN_8_320MV,///< Set Gain for shunt voltage.
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t_adc bus_adc = ADC_12BIT, ///< Configure bus voltage conversion.
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t_adc shunt_adc = ADC_12BIT, ///< Configure shun voltage conversion.
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t_mode mode = CONT_SH_BUS ///< Sets operation mode.
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);
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/// Resets the INA219.
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void reset();
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/// Returns the raw binary value of the shunt voltage
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int16_t shuntVoltageRaw() const;
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/// Returns raw bus voltage binary value.
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int16_t busVoltageRaw();
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/// Returns raw current binary value.
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int16_t shuntCurrentRaw() const;
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/// Returns the shunt voltage in volts.
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float shuntVoltage() const;
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/// Returns the bus voltage in volts.
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float busVoltage();
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/// Returns the shunt current in amps.
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float shuntCurrent() const;
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/// Returns the bus power in watts.
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float busPower() const;
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/// Rewrites last config value to INA219 register
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void reconfig() const;
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/// Rewrites last calibration value to INA219 register
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void recalibrate() const;
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/// conversion is ready
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bool ready() const;
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/// conversion is ready
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bool overflow() const;
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private:
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/// INA219 memory registers.
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enum t_reg{
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CONFIG_R = 0x00, ///< configuration register.
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V_SHUNT_R = 0x01, ///< differential shunt voltage.
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V_BUS_R = 0x02, ///< bus voltage (wrt to system/chip GND).
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P_BUS_R = 0x03, ///< system power draw (= V_BUS * I_SHUNT).
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I_SHUNT_R = 0x04, ///< shunt current.
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CAL_R = 0x05 ///< calibration register.
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};
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const uint8_t i2c_address;
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float r_shunt, current_lsb, power_lsb;
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uint16_t config, cal;
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bool _ready, _overflow;
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uint16_t _bus_voltage_register;
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///Read 16 word from given register address.
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int16_t read16( t_reg addr ///< Register address.
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) const;
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/// Writes a 16-bit word (d) to register pointer (a).
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/// When selecting a register pointer to read from, (d) = 0
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void write16( t_reg addr, ///< Register address.
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uint16_t data ///< Data to be writen.
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) const;
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};
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#endif
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