ina228.c

/*
 * INA228 - TI Current/Voltage/Power Monitor Code
 * Copyright (C) 2021 Craig Peacock
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <byteswap.h>
#include "i2c.h"
#include "ina228.h"

/*
 * SHUNT_CAL is a conversion constant that represents the shunt resistance
 * used to calculate current value in Amps. This also sets the resolution
 * (CURRENT_LSB) for the current register.
 *
 * SHUNT_CAL is 15 bits wide (0 - 32768)
 *
 * SHUNT_CAL = 13107.2 x 10^6 x CURRENT_LSB x Rshunt
 *
 * CURRENT_LSB = Max Expected Current / 2^19
 */

#define CURRENT_LSB 	0.000015625
#define SHUNT_CAL	1024

void ina228_init(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	i2c_write_short(i2c_master_port, i2c_slave_addr, INA228_CONFIG, 0x8000);	// Reset

	printf("Manufacturer ID: 0x%04X\r\n",i2c_read_short(i2c_master_port, INA228_SLAVE_ADDRESS, INA228_MANUFACTURER_ID));
	printf("Device ID:       0x%04X\r\n",i2c_read_short(i2c_master_port, INA228_SLAVE_ADDRESS, INA228_DEVICE_ID));

	i2c_write_short(i2c_master_port, i2c_slave_addr, INA228_SHUNT_CAL, SHUNT_CAL);
	printf("\r\n");
}

float ina228_voltage(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	int32_t iBusVoltage;
	float fBusVoltage;
	bool sign;

	i2c_read_buf(i2c_master_port, i2c_slave_addr, INA228_VBUS, (uint8_t *)&iBusVoltage, 3);
	sign = iBusVoltage & 0x80;
	iBusVoltage = bswap_32(iBusVoltage & 0xFFFFFF) >> 12;
	if (sign) iBusVoltage += 0xFFF00000;
	fBusVoltage = (iBusVoltage) * 0.0001953125;

	return (fBusVoltage);
}

float ina228_dietemp(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	uint16_t iDieTemp;
	float fDieTemp;

	iDieTemp = i2c_read_short(i2c_master_port, i2c_slave_addr, INA228_DIETEMP);
	fDieTemp = (iDieTemp) * 0.0078125;

	return (fDieTemp);
}

float ina228_shuntvoltage(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	int32_t iShuntVoltage;
	float fShuntVoltage;
	bool sign;

	i2c_read_buf(i2c_master_port, i2c_slave_addr, INA228_VSHUNT, (uint8_t *)&iShuntVoltage, 3);
	sign = iShuntVoltage & 0x80;
	iShuntVoltage = bswap_32(iShuntVoltage & 0xFFFFFF) >> 12;
	if (sign) iShuntVoltage += 0xFFF00000;

	fShuntVoltage = (iShuntVoltage) * 0.0003125;		// Output in mV when ADCRange = 0
	//fShuntVoltage = (iShuntVoltage) * 0.000078125;	// Output in mV when ADCRange = 1

	return (fShuntVoltage);
}

float ina228_current(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	int32_t iCurrent;
	float fCurrent;
	bool sign;

	i2c_read_buf(i2c_master_port, i2c_slave_addr, INA228_CURRENT, (uint8_t *)&iCurrent, 3);
	sign = iCurrent & 0x80;
	iCurrent = bswap_32(iCurrent & 0xFFFFFF) >> 12;
	if (sign) iCurrent += 0xFFF00000;
	fCurrent = (iCurrent) * CURRENT_LSB;

	return (fCurrent);
}

float ina228_power(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	uint32_t iPower;
	float fPower;

	i2c_read_buf(i2c_master_port, i2c_slave_addr, INA228_POWER, (uint8_t *)&iPower, 3);
	iPower = bswap_32(iPower & 0xFFFFFF) >> 8;
	fPower = 3.2 * CURRENT_LSB * iPower;

	return (fPower);
}

/*
 * Returns energy in Joules.
 * 1 Watt = 1 Joule per second
 * 1 W/hr = Joules / 3600
 */

float ina228_energy(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	uint64_t iEnergy;
	float fEnergy;

	i2c_read_buf(i2c_master_port, i2c_slave_addr, INA228_ENERGY, (uint8_t *)&iEnergy, 5);
	iEnergy = bswap_64(iEnergy & 0xFFFFFFFFFF) >> 24;

	fEnergy = 16 * 3.2 * CURRENT_LSB * iEnergy;

	return (fEnergy);
}

/*
 * Returns electric charge in Coulombs.
 * 1 Coulomb = 1 Ampere per second.
 * Hence Amp-Hours (Ah) = Coulombs / 3600
 */

float ina228_charge(uint32_t i2c_master_port, uint8_t i2c_slave_addr)
{
	int64_t iCharge;
	float fCharge;
	bool sign;

	i2c_read_buf(i2c_master_port, i2c_slave_addr, INA228_CHARGE, (uint8_t *)&iCharge, 5);
	sign = iCharge & 0x80;
	iCharge = bswap_64(iCharge & 0xFFFFFFFFFF) >> 24;
	if (sign) iCharge += 0xFFFFFF0000000000;

	fCharge = CURRENT_LSB * iCharge;

	return (fCharge);
}