299 lines
9.4 KiB
C++
299 lines
9.4 KiB
C++
|
/******************************************************************************
|
||
|
|
* TI INA219 hi-side i2c current/power monitor Library
|
||
|
|
*
|
||
|
|
* http://www.ti.com/product/ina219
|
||
|
|
*
|
||
|
|
* 6 May 2012 by John De Cristofaro
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* Tested at standard i2c 100kbps signaling rate.
|
||
|
|
*
|
||
|
|
* This library does not handle triggered conversion modes. It uses the INA219
|
||
|
|
* in continuous conversion mode. All reads are from continous conversions.
|
||
|
|
*
|
||
|
|
* A note about the gain (PGA) setting:
|
||
|
|
* The gain of the ADC pre-amplifier is programmable in the INA219, and can
|
||
|
|
* be set between 1/8x (default) and unity. This allows a shunt voltage
|
||
|
|
* range of +/-320mV to +/-40mV respectively. Something to keep in mind,
|
||
|
|
* however, is that this change in gain DOES NOT affect the resolution
|
||
|
|
* of the ADC, which is fixed at 1uV. What it does do is increase noise
|
||
|
|
* immunity by exploiting the integrative nature of the delta-sigma ADC.
|
||
|
|
* For the best possible reading, you should set the gain to the range
|
||
|
|
* of voltages that you expect to see in your particular circuit. See
|
||
|
|
* page 15 in the datasheet for more info about the PGA.
|
||
|
|
*
|
||
|
|
* Known bugs:
|
||
|
|
* * may return unreliable values if not connected to a bus or at
|
||
|
|
* bus currents below 10uA.
|
||
|
|
*
|
||
|
|
* Arduino 1.0 compatible as of 6/6/2012
|
||
|
|
*
|
||
|
|
* Dependencies:
|
||
|
|
* * Arduino Wire library
|
||
|
|
*
|
||
|
|
* MIT license
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include "INA219.h"
|
||
|
|
#define _delay_ms(ms) delayMicroseconds((ms) * 1000)
|
||
|
|
namespace{
|
||
|
|
// config. register bit labels
|
||
|
|
const uint8_t RST = 15;
|
||
|
|
const uint8_t BRNG = 13;
|
||
|
|
const uint8_t PG1 = 12;
|
||
|
|
const uint8_t PG0 = 11;
|
||
|
|
const uint8_t BADC4 = 10;
|
||
|
|
const uint8_t BADC3 = 9;
|
||
|
|
const uint8_t BADC2 = 8;
|
||
|
|
const uint8_t BADC1 = 7;
|
||
|
|
const uint8_t SADC4 = 6;
|
||
|
|
const uint8_t SADC3 = 5;
|
||
|
|
const uint8_t SADC2 = 4;
|
||
|
|
const uint8_t SADC1 = 3;
|
||
|
|
const uint8_t MODE3 = 2;
|
||
|
|
const uint8_t MODE2 = 1;
|
||
|
|
const uint8_t MODE1 = 0;
|
||
|
|
};
|
||
|
|
|
||
|
|
#define CNVR_B 1 // conversion ready bit in bus voltage register V_BUS_R
|
||
|
|
#define OVF_B 0 // math overflow bit in bus voltage register V_BUS_R
|
||
|
|
|
||
|
|
INA219::INA219(t_i2caddr addr): i2c_address(addr) {
|
||
|
|
}
|
||
|
|
|
||
|
|
void INA219::begin() {
|
||
|
|
Wire.begin();
|
||
|
|
configure();
|
||
|
|
calibrate();
|
||
|
|
}
|
||
|
|
|
||
|
|
void INA219::calibrate(float shunt_val, float v_shunt_max, float v_bus_max, float i_max_expected) {
|
||
|
|
uint16_t digits;
|
||
|
|
float i_max_possible, min_lsb, max_lsb, swap;
|
||
|
|
|
||
|
|
#if (INA219_DEBUG == 1)
|
||
|
|
float max_current,max_before_overflow,max_shunt_v,max_shunt_v_before_overflow,max_power;
|
||
|
|
#endif
|
||
|
|
r_shunt = shunt_val;
|
||
|
|
|
||
|
|
i_max_possible = v_shunt_max / r_shunt;
|
||
|
|
min_lsb = i_max_expected / 32767;
|
||
|
|
max_lsb = i_max_expected / 4096;
|
||
|
|
|
||
|
|
current_lsb = min_lsb;
|
||
|
|
digits=0;
|
||
|
|
|
||
|
|
/* From datasheet: This value was selected to be a round number near the Minimum_LSB.
|
||
|
|
* This selection allows for good resolution with a rounded LSB.
|
||
|
|
* eg. 0.000610 -> 0.000700
|
||
|
|
*/
|
||
|
|
while( current_lsb > 0.0 ){//If zero there is something weird...
|
||
|
|
if( (uint16_t)current_lsb / 1){
|
||
|
|
current_lsb = (uint16_t) current_lsb + 1;
|
||
|
|
current_lsb /= pow(10,digits);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
else{
|
||
|
|
digits++;
|
||
|
|
current_lsb *= 10.0;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
swap = (0.04096)/(current_lsb*r_shunt);
|
||
|
|
cal = (uint16_t)swap;
|
||
|
|
power_lsb = current_lsb * 20;
|
||
|
|
|
||
|
|
#if (INA219_DEBUG == 1)
|
||
|
|
max_current = current_lsb*32767;
|
||
|
|
max_before_overflow = max_current > i_max_possible?i_max_possible:max_current;
|
||
|
|
|
||
|
|
max_shunt_v = max_before_overflow*r_shunt;
|
||
|
|
max_shunt_v_before_overflow = max_shunt_v > v_shunt_max?v_shunt_max:max_shunt_v;
|
||
|
|
|
||
|
|
max_power = v_bus_max * max_before_overflow;
|
||
|
|
Serial.print("v_bus_max: "); Serial.println(v_bus_max, 8);
|
||
|
|
Serial.print("v_shunt_max: "); Serial.println(v_shunt_max, 8);
|
||
|
|
Serial.print("i_max_possible: "); Serial.println(i_max_possible, 8);
|
||
|
|
Serial.print("i_max_expected: "); Serial.println(i_max_expected, 8);
|
||
|
|
Serial.print("min_lsb: "); Serial.println(min_lsb, 12);
|
||
|
|
Serial.print("max_lsb: "); Serial.println(max_lsb, 12);
|
||
|
|
Serial.print("current_lsb: "); Serial.println(current_lsb, 12);
|
||
|
|
Serial.print("power_lsb: "); Serial.println(power_lsb, 8);
|
||
|
|
Serial.println(" ");
|
||
|
|
Serial.print("cal: "); Serial.println(cal);
|
||
|
|
Serial.print("r_shunt: "); Serial.println(r_shunt, 6);
|
||
|
|
Serial.print("max_before_overflow: "); Serial.println(max_before_overflow,8);
|
||
|
|
Serial.print("max_shunt_v_before_overflow: "); Serial.println(max_shunt_v_before_overflow,8);
|
||
|
|
Serial.print("max_power: "); Serial.println(max_power,8);
|
||
|
|
Serial.println(" ");
|
||
|
|
#endif
|
||
|
|
write16(CAL_R, cal);
|
||
|
|
}
|
||
|
|
|
||
|
|
void INA219::configure( t_range range, t_gain gain, t_adc bus_adc, t_adc shunt_adc, t_mode mode) {
|
||
|
|
config = 0;
|
||
|
|
|
||
|
|
config |= (range << BRNG | gain << PG0 | bus_adc << BADC1 | shunt_adc << SADC1 | mode);
|
||
|
|
#if (INA219_DEBUG == 1)
|
||
|
|
Serial.print("Config: 0x"); Serial.println(config,HEX);
|
||
|
|
#endif
|
||
|
|
write16(CONFIG_R, config);
|
||
|
|
}
|
||
|
|
|
||
|
|
#define INA_RESET 0xFFFF // send to CONFIG_R to reset unit
|
||
|
|
void INA219::reset(){
|
||
|
|
write16(CONFIG_R, INA_RESET);
|
||
|
|
_delay_ms(5);
|
||
|
|
}
|
||
|
|
|
||
|
|
int16_t INA219::shuntVoltageRaw() const {
|
||
|
|
return read16(V_SHUNT_R);
|
||
|
|
}
|
||
|
|
|
||
|
|
float INA219::shuntVoltage() const {
|
||
|
|
float temp;
|
||
|
|
temp = read16(V_SHUNT_R);
|
||
|
|
return (temp / 100000);
|
||
|
|
}
|
||
|
|
|
||
|
|
int16_t INA219::busVoltageRaw() {
|
||
|
|
_bus_voltage_register = read16(V_BUS_R);
|
||
|
|
_overflow = bitRead(_bus_voltage_register, OVF_B); // overflow bit
|
||
|
|
_ready = bitRead(_bus_voltage_register, CNVR_B); // ready bit
|
||
|
|
return _bus_voltage_register;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
float INA219::busVoltage() {
|
||
|
|
int16_t temp;
|
||
|
|
temp = busVoltageRaw();
|
||
|
|
temp >>= 3;
|
||
|
|
return (temp * 0.004);
|
||
|
|
}
|
||
|
|
|
||
|
|
int16_t INA219::shuntCurrentRaw() const {
|
||
|
|
return (read16(I_SHUNT_R));
|
||
|
|
}
|
||
|
|
|
||
|
|
float INA219::shuntCurrent() const {
|
||
|
|
return (read16(I_SHUNT_R) * current_lsb);
|
||
|
|
}
|
||
|
|
|
||
|
|
float INA219::busPower() const {
|
||
|
|
return (read16(P_BUS_R) * power_lsb);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**************************************************************************/
|
||
|
|
/*!
|
||
|
|
@brief Rewrites the last config register
|
||
|
|
*/
|
||
|
|
/**************************************************************************/
|
||
|
|
void INA219::reconfig() const {
|
||
|
|
#if (INA219_DEBUG == 1)
|
||
|
|
Serial.print("Reconfigure with Config: 0x"); Serial.println(config,HEX);
|
||
|
|
#endif
|
||
|
|
write16(CONFIG_R, config);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**************************************************************************/
|
||
|
|
/*!
|
||
|
|
@brief Rewrites the last calibration
|
||
|
|
*/
|
||
|
|
/**************************************************************************/
|
||
|
|
void INA219::recalibrate() const {
|
||
|
|
#if (INA219_DEBUG == 1)
|
||
|
|
Serial.print("Recalibrate with cal: "); Serial.println(cal);
|
||
|
|
#endif
|
||
|
|
write16(CAL_R, cal);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**************************************************************************/
|
||
|
|
/*!
|
||
|
|
@brief returns conversion ready bite from last bus voltage read
|
||
|
|
|
||
|
|
@note page 30:
|
||
|
|
Although the data from the last conversion can be read at any time,
|
||
|
|
the INA219 Conversion Ready bit (CNVR) indicates when data from
|
||
|
|
a conversion is available in the data output registers.
|
||
|
|
The CNVR bit is set after all conversions, averaging,
|
||
|
|
and multiplications are complete.
|
||
|
|
CNVR will clear under the following conditions:
|
||
|
|
1.) Writing a new mode into the Operating Mode bits in the
|
||
|
|
Configuration Register (except for Power-Down or Disable)
|
||
|
|
2.) Reading the Power Register
|
||
|
|
|
||
|
|
page 15:
|
||
|
|
The Conversion Ready bit clears under these
|
||
|
|
conditions:
|
||
|
|
1. Writing to the Configuration Register, except
|
||
|
|
when configuring the MODE bits for Power Down
|
||
|
|
or ADC off (Disable) modes;
|
||
|
|
2. Reading the Status Register;
|
||
|
|
3. Triggering a single-shot conversion with the
|
||
|
|
Convert pin.
|
||
|
|
*/
|
||
|
|
/**************************************************************************/
|
||
|
|
bool INA219::ready() const {
|
||
|
|
return _ready;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**************************************************************************/
|
||
|
|
/*!
|
||
|
|
@brief returns overflow bite from last bus voltage read
|
||
|
|
|
||
|
|
@note The Math Overflow Flag (OVF) is set when the Power or
|
||
|
|
Current calculations are out of range. It indicates that
|
||
|
|
current and power data may be meaningless.
|
||
|
|
*/
|
||
|
|
/**************************************************************************/
|
||
|
|
bool INA219::overflow() const {
|
||
|
|
return _overflow;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**********************************************************************
|
||
|
|
* INTERNAL I2C FUNCTIONS *
|
||
|
|
**********************************************************************/
|
||
|
|
|
||
|
|
void INA219::write16(t_reg a, uint16_t d) const {
|
||
|
|
uint8_t temp;
|
||
|
|
temp = (uint8_t)d;
|
||
|
|
d >>= 8;
|
||
|
|
Wire.beginTransmission(i2c_address); // start transmission to device
|
||
|
|
|
||
|
|
#if ARDUINO >= 100
|
||
|
|
Wire.write(a); // sends register address to read from
|
||
|
|
Wire.write((uint8_t)d); // write data hibyte
|
||
|
|
Wire.write(temp); // write data lobyte;
|
||
|
|
#else
|
||
|
|
Wire.send(a); // sends register address to read from
|
||
|
|
Wire.send((uint8_t)d); // write data hibyte
|
||
|
|
Wire.send(temp); // write data lobyte;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
Wire.endTransmission(); // end transmission
|
||
|
|
delay(1);
|
||
|
|
}
|
||
|
|
|
||
|
|
int16_t INA219::read16(t_reg a) const {
|
||
|
|
uint16_t ret;
|
||
|
|
|
||
|
|
// move the pointer to reg. of interest, null argument
|
||
|
|
write16(a, 0);
|
||
|
|
|
||
|
|
Wire.requestFrom((int)i2c_address, 2); // request 2 data bytes
|
||
|
|
|
||
|
|
#if ARDUINO >= 100
|
||
|
|
ret = Wire.read(); // rx hi byte
|
||
|
|
ret <<= 8;
|
||
|
|
ret |= Wire.read(); // rx lo byte
|
||
|
|
#else
|
||
|
|
ret = Wire.receive(); // rx hi byte
|
||
|
|
ret <<= 8;
|
||
|
|
ret |= Wire.receive(); // rx lo byte
|
||
|
|
#endif
|
||
|
|
|
||
|
|
Wire.endTransmission(); // end transmission
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|