// FILE: INA219.h // AUTHOR: Rob Tillaart // VERSION: 0.1.2 // DATE: 2021-05-18 // PURPOSE: Arduino library for INA219 voltage, current and power sensor // URL: https://github.com/RobTillaart/INA219 // // HISTORY: see changelog.md #include "INA219.h" // REGISTER ADDRESSES #define INA219_CONFIGURATION 0x00 #define INA219_SHUNT_VOLTAGE 0x01 #define INA219_BUS_VOLTAGE 0x02 #define INA219_POWER 0x03 #define INA219_CURRENT 0x04 #define INA219_CALIBRATION 0x05 #define INA219_MASK_ENABLE 0x06 #define INA219_ALERT_LIMIT 0x07 #define INA219_MANUFACTURER 0xFE #define INA219_DIE_ID 0xFF // CONFIGURATION REGISTER MASKS #define INA219_CONF_RESET 0x8000 #define INA219_CONF_BUS_RANGE_VOLTAGE 0x2000 #define INA219_CONF_PROG_GAIN 0x1800 #define INA219_CONF_BUS_ADC 0x0780 #define INA219_CONF_SHUNT_ADC 0x0078 #define INA219_CONF_MODE 0x0007 //////////////////////////////////////////////////////// // // CONSTRUCTOR // INA219::INA219(const uint8_t address, TwoWire *wire) { _address = address; _wire = wire; // not calibrated values by default. _current_LSB = 0; _maxCurrent = 0; _shunt = 0; } #if defined (ESP8266) || defined(ESP32) bool INA219::begin(const uint8_t sda, const uint8_t scl) { _wire = &Wire; _wire->begin(sda, scl); if (! isConnected()) return false; return true; } #endif bool INA219::begin() { _wire->begin(); if (! isConnected()) return false; return true; } bool INA219::isConnected() { _wire->beginTransmission(_address); return ( _wire->endTransmission() == 0); } //////////////////////////////////////////////////////// // // CORE FUNCTIONS // float INA219::getShuntVoltage() { uint16_t value = _readRegister(INA219_SHUNT_VOLTAGE); return value * 1e-5; // fixed 10 uV } float INA219::getBusVoltage() { uint16_t value = _readRegister(INA219_BUS_VOLTAGE); uint8_t flags = value & 0x03; // overflow handling if (flags & 0x01) return -100; float voltage = (value >> 3) * 4e-3; // fixed 4 mV return voltage; } float INA219::getPower() { uint16_t value = _readRegister(INA219_POWER); return value * 20 * _current_LSB; } // TODO CHECK // needs _current_LSB factor? float INA219::getCurrent() { int16_t value = _readRegister(INA219_CURRENT); return value * _current_LSB; } //////////////////////////////////////////////////////// // // CONFIGURATION // void INA219::reset() { uint16_t config = _readRegister(INA219_CONFIGURATION); config |= 0x8000; _writeRegister(INA219_CONFIGURATION, config); // reset calibration _current_LSB = 0; _maxCurrent = 0; _shunt = 0; } bool INA219::setBusVoltageRange(uint8_t voltage) { if (voltage > 32) return false; if (voltage > 16) voltage = 32; else voltage = 16; uint16_t config = _readRegister(INA219_CONFIGURATION); config &= ~INA219_CONF_BUS_RANGE_VOLTAGE; if (voltage == 32) config |= INA219_CONF_BUS_RANGE_VOLTAGE; _writeRegister(INA219_CONFIGURATION, config); return true; } uint8_t INA219::getBusVoltageRange() { uint16_t config = _readRegister(INA219_CONFIGURATION); if (config & INA219_CONF_BUS_RANGE_VOLTAGE) return 32; return 16; } bool INA219::setGain(uint8_t factor) { if (factor != 1 && factor != 2 && factor != 4 && factor != 8) { return false; } uint16_t config = _readRegister(INA219_CONFIGURATION); config &= ~INA219_CONF_PROG_GAIN; if (factor == 2) config |= (1 << 11); else if (factor == 4) config |= (2 << 11); else if (factor == 8) config |= (3 << 11); _writeRegister(INA219_CONFIGURATION, config); return true; } uint8_t INA219::getGain() { uint16_t config = _readRegister(INA219_CONFIGURATION); uint16_t mask = (config & INA219_CONF_PROG_GAIN); if (mask == 0x0000) return 1; else if (mask == 0x0800) return 2; else if (mask == 0x1000) return 4; return 8; } bool INA219::setBusADC(uint8_t mask) { if (mask > 0x000F) return false; // TODO improve this one. datasheet. // two functions // setBusResolution + setBusSamples() uint16_t config = _readRegister(INA219_CONFIGURATION); config &= ~INA219_CONF_BUS_ADC; config |= (mask << 7); // if (bits == 10) config |= (1 << 7); // else if (bits == 11) config |= (2 << 7); // else if (bits == 12) config |= (3 << 7); _writeRegister(INA219_CONFIGURATION, config); return true; } uint8_t INA219::getBusADC() { uint16_t config = _readRegister(INA219_CONFIGURATION); config &= INA219_CONF_BUS_ADC; return config >> 7; } bool INA219::setShuntADC(uint8_t mask) { if (mask > 0x000F) return false; // TODO improve this one. datasheet. // two functions // setShuntResolution + setShuntSamples() uint16_t config = _readRegister(INA219_CONFIGURATION); config &= ~INA219_CONF_SHUNT_ADC; config |= (mask << 3); _writeRegister(INA219_CONFIGURATION, config); return true; } uint8_t INA219::getShuntADC() { uint16_t config = _readRegister(INA219_CONFIGURATION); config &= INA219_CONF_SHUNT_ADC; return config >> 3; } bool INA219::setMode(uint8_t mode) { if (mode > 8) return false; uint16_t config = _readRegister(INA219_CONFIGURATION); config &= ~INA219_CONF_MODE; config |= mode; _writeRegister(INA219_CONFIGURATION, config); return true; } uint8_t INA219::getMode() { uint16_t config = _readRegister(INA219_CONFIGURATION); config &= INA219_CONF_MODE; return config; } //////////////////////////////////////////////////////// // // CALIBRATION // bool INA219::setMaxCurrentShunt(float maxCurrent, float shunt) { #define printdebug true uint16_t calib = 0; if (maxCurrent < 0.001) return false; if (shunt < 0.001) return false; // _current_LSB = maxCurrent / 32768; _current_LSB = maxCurrent * 3.0517578125e-5; _maxCurrent = maxCurrent; _shunt = shunt; calib = round(0.04096 / (_current_LSB * shunt)); _writeRegister(INA219_CALIBRATION, calib); #ifdef printdebug Serial.println(); Serial.print("current_LSB:\t"); Serial.print(_current_LSB, 8); Serial.println(" uA / bit"); Serial.print("Calibration:\t"); Serial.println(calib); Serial.print("Max current:\t"); Serial.print(_maxCurrent, 3); Serial.println(" A"); Serial.print("Shunt:\t"); Serial.print(_shunt, 8); Serial.println(" ohm Ω"); #endif return true; } //////////////////////////////////////////////////////// // // PRIVATE // uint16_t INA219::_readRegister(uint8_t reg) { _wire->beginTransmission(_address); _wire->write(reg); _wire->endTransmission(); _wire->requestFrom(_address, (uint8_t)2); uint16_t value = _wire->read(); value <<= 8; value |= _wire->read(); return value; } uint16_t INA219::_writeRegister(uint8_t reg, uint16_t value) { _wire->beginTransmission(_address); _wire->write(reg); _wire->write(value >> 8); _wire->write(value & 0xFF); return _wire->endTransmission(); } // -- END OF FILE --