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ltc2943.cpp
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/* mbed Microcontroller Library
* Copyright (c) 2017 u-blox
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file ltc2943.cpp
* This file defines the API to the Linear Technology LTC2943 battery gauge chip.
*/
/// Define this to print debug information.
//#define DEBUG_LTC2943
#include <mbed.h>
#include <battery_gauge_ltc2943.h>
#ifdef DEBUG_LTC2943
# include <stdio.h>
#endif
// ----------------------------------------------------------------
// COMPILE-TIME MACROS
// ----------------------------------------------------------------
/// How long to wait for one ADC read of temperature, voltage and current
// to be performed.
#define ADC_READ_WAIT_MS 100
/// The tolerance allowed for value conversions into the threshold registers.
#define LTC_2943_TOLERANCE 2
/// Check that a value is within tolerance.
#define TOLERANCE_CHECK(value, intendedValue, tolerance) ((value - intendedValue <= tolerance) && (value - intendedValue >= -tolerance))
// ----------------------------------------------------------------
// PRIVATE VARIABLES
// ----------------------------------------------------------------
// ----------------------------------------------------------------
// GENERIC PRIVATE FUNCTIONS
// ----------------------------------------------------------------
/// Read two bytes from an address.
// Note: gpI2c should be locked before this is called.
bool BatteryGaugeLtc2943::getTwoBytes (uint8_t registerAddress, uint16_t *pBytes)
{
bool success = false;
char data[3];
if (gpI2c != NULL) {
// Send a command to read from registerAddress
data[0] = registerAddress;
data[1] = 0;
data[2] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 2) == 0)) {
success = true;
if (pBytes) {
*pBytes = (((uint16_t) data[1]) << 8) + data[2];
}
}
}
return success;
}
/// Set two bytes, starting from an address.
// Note: gpI2c should be locked before this is called.
bool BatteryGaugeLtc2943::setTwoBytes (uint8_t registerAddress, uint16_t bytes)
{
bool success = false;
char data[3];
if (gpI2c != NULL) {
// Send a command to write from registerAddress
data[0] = registerAddress;
data[1] = (char) (bytes >> 8);
data[2] = (char) bytes;
if (gpI2c->write(gAddress, &(data[0]), 3) == 0) {
success = true;
}
}
return success;
}
/// Ensure that the ADC of the chip has taken a reading recently.
// Note: gpI2c should be locked before this is called.
bool BatteryGaugeLtc2943::makeAdcReading (void)
{
bool success = false;
char storedControlRegister;
char data[2];
if (gReady && (gpI2c != NULL)){
// Read the control register
data[0] = 0x01; // Address of the control register
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
storedControlRegister = data[1];
// If the ADC mode, in bits 6 and 7, is zero, set
// it to 01, which will take a manual reading of voltage,
// current and temperature and then return them to zero.
// Also make sure that the power-down bit is not set.
if ((data[1] & 0xC0) == 0) {
data[1] |= 0x40;
data[1] &= ~0x01;
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
wait_ms(ADC_READ_WAIT_MS);
// Now set the shutdown bit to ensure lowest power state
data[1] = storedControlRegister | 0x01;
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
}
}
} else {
// Readings are already being made, nothing to do here
success = true;
}
}
}
return success;
}
/// Convert a 16 bit register reading into a temperature reading in C.
// Note: gpI2c should be locked before this is called.
int32_t BatteryGaugeLtc2943::registerToTemperatureC (uint16_t data)
{
// From the data sheet the temperature (in Kelvin) is
// T = 510 * data / 0xffff
return (((uint32_t) data) * 510 / 0xffff) - 273;
}
/// Convert a temperature in C to a register value.
// Note: no overflow checking is done here, such effects must be checked by the caller.
uint16_t BatteryGaugeLtc2943::temperatureCToRegister (int32_t temperatureC)
{
int32_t registerValue;
// Check against the laws of physics
MBED_ASSERT (temperatureC >= -273);
// Rearranging from the above
registerValue = (temperatureC + 273) * 0xffff / 510;
if (registerValue > 0xffff) {
registerValue = 0xffff;
}
if (registerValue < 0) {
registerValue = 0;
}
return (uint16_t) registerValue;
}
/// Convert a 16 bit register reading into a voltage reading in mV.
int32_t BatteryGaugeLtc2943::registerToVoltageMV (uint16_t data)
{
// From the data sheet the voltage (in mV) is
// V = 23600 * data / 0xffff
return (((int32_t) data) * 23600) / 0xffff;
}
/// Convert a voltage in mV to a register value.
// Note: no overflow checking is done here, such effects must be checked by the caller.
uint16_t BatteryGaugeLtc2943::voltageMVToRegister (int32_t voltageMV)
{
int32_t registerValue;
// Rearranging from the above
registerValue = (voltageMV * 0xffff) / 23600;
if (registerValue > 0xffff) {
registerValue = 0xffff;
}
if (registerValue < 0) {
registerValue = 0;
}
return (uint16_t) registerValue;
}
/// Convert a 16 bit register reading into a current reading in mA.
int32_t BatteryGaugeLtc2943::registerToCurrentMA (uint16_t data, int32_t rSenseMOhm)
{
// From the data sheet, max current (in Amps) corresponds to 0xffff
// (which is 60 mV across RSense) while min (most negative)
// current corresponds to 0 (which is -60 mV across RSense).
return ((int32_t) (data - 0x7fff)) * 60 * 1000 / 0x7fff / rSenseMOhm;
}
/// Convert a current in mA to a register value.
// Note: no overflow checking is done here, such effects must be checked by the caller.
uint16_t BatteryGaugeLtc2943::currentMAToRegister (int32_t currentMA, int32_t rSenseMOhm)
{
int32_t registerValue;
int32_t value = currentMA * rSenseMOhm;
// Rearranging from the above
registerValue = ((value) * 544 / 1000) + 0x7fff;
if (registerValue > 0xffff) {
registerValue = 0xffff;
}
if (registerValue < 0) {
registerValue = 0;
}
return (uint16_t) registerValue;
}
/// Convert a 16 bit register reading into a charge reading in mAh.
int32_t BatteryGaugeLtc2943::registerToChargeMAH (uint16_t data, int32_t rSenseMOhm, int32_t prescaler)
{
// From the data sheet, each bit of the charge registers has
// the following value in mAh:
// 0.34 * 50 * prescaler / RSense / 4096.
return ((((int32_t) data) * 17 * prescaler) / rSenseMOhm) >> 12;
}
/// Convert a charge in mAh to a register value.
// Note: no overflow checking is done here, such effects must be checked by the caller.
uint16_t BatteryGaugeLtc2943::chargeMAHToRegister (int32_t chargeMAH, int32_t rSenseMOhm, int32_t prescaler)
{
int32_t registerValue;
// Rearranging from the above
registerValue = ((chargeMAH << 12) * rSenseMOhm) / prescaler / 17;
if (registerValue > 0xffff) {
registerValue = 0xffff;
}
if (registerValue < 0) {
registerValue = 0;
}
return (uint16_t) registerValue;
}
//----------------------------------------------------------------
// PUBLIC FUNCTIONS: initialisation and monitoring
//----------------------------------------------------------------
/// Constructor.
BatteryGaugeLtc2943::BatteryGaugeLtc2943(void)
{
gpI2c = NULL;
gReady = false;
gBatteryCapacityMAH = 0;
}
/// Destructor.
BatteryGaugeLtc2943::~BatteryGaugeLtc2943(void)
{
}
/// Initialise ourselves.
bool BatteryGaugeLtc2943::init (I2C * pI2c, int32_t rSenseMOhm, uint8_t address, int32_t prescaler, Alcc alcc)
{
char data[2];
gpI2c = pI2c;
gAddress = address << 1;
gRSenseMOhm = rSenseMOhm;
gPrescaler = prescaler;
MBED_ASSERT(alcc < MAX_NUM_ALCCS);
if (gpI2c != NULL) {
gpI2c->lock();
// Set up the prescaler, ALCC and set everything to lowest power state for now
data[0] = 0x01; // Address of the control register
// Bits 7:6 top two bits zero == ADC asleep
// Bits 5:3 coded prescaler value
// Bits 2:1 ALCC mode (10 for Alert Output, 01 for Charge Complete Input, 00 for Off
// Bit 0 1 to power down analogue components
data[1] = 0x01;
data[1] |= alcc << 1;
switch (prescaler) {
case 1:
// Coded prescaler value is zero, nothing to do
break;
case 4:
data[1] |= 1 << 3;
break;
case 16:
data[1] |= 2 << 3;
break;
case 64:
data[1] |= 3 << 3;
break;
case 256:
data[1] |= 4 << 3;
break;
case 1024:
data[1] |= 5 << 3;
break;
case 4096:
data[1] |= 6 << 3;
break;
default:
gPrescaler = 0;
MBED_ASSERT(false);
break;
}
// Now write to the control register
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
gReady = true;
}
gpI2c->unlock();
}
#ifdef DEBUG_LTC2943
if (gReady) {
printf("BatteryGaugeLtc2943 (I2C 0x%02x): handler initialised (control register set to 0x%02x).\n", gAddress >> 1, data[1]);
} else {
printf("BatteryGaugeLtc2943 (I2C 0x%02x): device NOT found.\r\n", gAddress >> 1);
}
#endif
return gReady;
}
/// Switch battery charge monitoring on.
bool BatteryGaugeLtc2943::enableGauge (bool isSlow)
{
bool success = false;
char data[2];
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
// Read the control register
data[0] = 0x01; // Address of the control register
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
// Set the ADC mode in bits 6 and 7 to 11 or, if
// isSlow is true, to 10 (in which case a measurement
// is only performed every ten seconds).
data[1] |= 0xc0;
if (isSlow) {
data[1] &= ~0x40;
}
// Also make sure that the power-down bit is not set.
data[1] &= ~0x01;
// Write the new value to the control register
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
}
}
gpI2c->unlock();
}
return success;
}
/// Switch battery charge monitoring off.
bool BatteryGaugeLtc2943::disableGauge (void)
{
bool success = false;
char data[2];
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
// Read the control register
data[0] = 0x01; // Address of the control register
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
// Set the ADC mode to 00 and the power down bit to 1
data[1] &= ~0xc0;
data[1] |= 0x01;
// Write the new value to the control register
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
}
}
gpI2c->unlock();
}
return success;
}
//----------------------------------------------------------------
// PUBLIC FUNCTIONS: getting readings
//----------------------------------------------------------------
/// Get the temperature of the chip.
bool BatteryGaugeLtc2943::getTemperature (int32_t *pTemperatureC)
{
bool success = false;
uint16_t data;
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
if (makeAdcReading ()) {
// Read from the temperature register address
if (getTwoBytes (0x14, &data)) {
success = true;
if (pTemperatureC) {
*pTemperatureC = registerToTemperatureC (data);
}
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature registers report 0x%04x, so %d C.\n",
gAddress >> 1, data, registerToTemperatureC (data));
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Get the voltage of the battery.
bool BatteryGaugeLtc2943::getVoltage (int32_t *pVoltageMV)
{
bool success = false;
uint16_t data;
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
if (makeAdcReading()) {
// Read from the voltage register address
if (getTwoBytes (0x08, &data)) {
success = true;
if (pVoltageMV) {
*pVoltageMV = registerToVoltageMV (data);
}
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): voltage registers report 0x%04x, giving a voltage of %.3f V.\n",
gAddress >> 1, data, (float) registerToVoltageMV (data) / 1000);
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Get the current flowing through RSense.
bool BatteryGaugeLtc2943::getCurrent (int32_t *pCurrentMA)
{
bool success = false;
uint16_t data;
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
if (makeAdcReading()) {
// Read from the current register address
if (getTwoBytes (0x0e, &data)) {
success = true;
if (pCurrentMA) {
*pCurrentMA = registerToCurrentMA (data, gRSenseMOhm);
}
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): current registers report 0x%04x, giving a current of %.3f A.\n",
gAddress >> 1, data, (float) registerToCurrentMA (data, gRSenseMOhm) / 1000);
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Tell the LTC2943 chip that charging is complete.
bool BatteryGaugeLtc2943::setChargingComplete (int32_t capacityMAH)
{
bool success = false;
bool analoguePowerReady = true;
char data[2];
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
// First read the control register as we have to power
// down the analogue parts when setting the charge registers
data[0] = 0x01; // Address of the control register
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
// If the power down bit is not set, set it
if ((data[1] & 0x01) != 0x01) {
data[1] |= 0x01;
if (gpI2c->write(gAddress, &(data[0]), 2) != 0) {
analoguePowerReady = false;
}
}
if (analoguePowerReady) {
// Remember the battery charge
gBatteryCapacityMAH = capacityMAH;
// Set the charge counter to max
success = setTwoBytes(0x02, 0xffff);
// If the ADC mode, in bits 6 and 7, is not zero then
// we must switch on the analogue power again.
if ((data[1] & 0xc0) != 0) {
data[1] &= ~0x01;
if (gpI2c->write(gAddress, &(data[0]), 2) != 0) {
success = false;
}
}
}
}
gpI2c->unlock();
}
return success;
}
/// Get the remaining battery charge.
bool BatteryGaugeLtc2943::getRemainingCharge (int32_t *pChargeMAH)
{
bool success = false;
int32_t chargeMAH;
uint16_t data;
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
// Read from the charge accumulator register address
if (getTwoBytes (0x02, &data)) {
success = true;
// Full scale corresponds to the capacity of the battery when
// fully charged, so the capacity used is 0xffff - data
chargeMAH = registerToChargeMAH (0xffff - data, gRSenseMOhm, gPrescaler);
if (pChargeMAH) {
*pChargeMAH = gBatteryCapacityMAH - chargeMAH;
if (gBatteryCapacityMAH == 0) {
// If gBatteryCapacityMAH is 0, we can't actually calculate the remaining
// capacity but we can calculate the charge used using the fact that the default
// starting value is 0x7FFF. So set success to false so that the user knows
// we can't supply what was requested but report the charge used number anyway
// in case it is useful
success = false;
*pChargeMAH = registerToChargeMAH (0x7FFF - data, gRSenseMOhm, gPrescaler);
}
}
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): charge accumulator registers report 0x%04x, battery capacity is %d giving a charge remaining of %.3f AH.\n",
gAddress >> 1, data, gBatteryCapacityMAH, (float) (gBatteryCapacityMAH - chargeMAH) / 1000);
#endif
}
gpI2c->unlock();
}
return success;
}
/// Get the battery percentage remaining.
bool BatteryGaugeLtc2943::getRemainingPercentage (int32_t *pBatteryPercent)
{
bool success;
int32_t chargeMAH;
success = getRemainingCharge (&chargeMAH);
if (success) {
if (pBatteryPercent) {
*pBatteryPercent = 100 * gBatteryCapacityMAH / chargeMAH;
}
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): remaining charge is %d mAh, battery capacity is %d mAh, so percentage remaining is %d%%.\n",
gAddress >> 1, chargeMAH, gBatteryCapacityMAH, 100 * gBatteryCapacityMAH / chargeMAH);
#endif
}
return success;
}
/// Get the reason(s) for an alert.
char BatteryGaugeLtc2943::getAlertReason (void)
{
char result = 0;
char data[2];
if (gReady && (gpI2c != NULL)){
gpI2c->lock();
data[0] = 0x00; // Address of the control register
data[1] = 0;
// Read the status register
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1))) {
result = data[1];
}
gpI2c->unlock();
}
return result;
}
//----------------------------------------------------------------
// PUBLIC FUNCTIONS: setting/getting/checking/clearing thresholds
//----------------------------------------------------------------
/// Set temperature alert upper threshold.
bool BatteryGaugeLtc2943::setTemperatureHigh (int32_t temperatureC)
{
bool success = false;
uint16_t registerValue = temperatureCToRegister(temperatureC);
char data[2];
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
registerValue >>= 8;
// Check for overflow in conversion to the register value
printf ("registerValue %d, temperatureC %d, registerToTemperatureC(registerValue << 8) %d\n",
registerValue, (int) temperatureC, (int) registerToTemperatureC(registerValue << 8));
if (TOLERANCE_CHECK (registerToTemperatureC(registerValue << 8), temperatureC, LTC_2943_TOLERANCE)) {
data[0] = 0x16; // Temperature threshold high address
// Only write the value if it fits (and taking into
// account the fact that 0xFF means "no upper threshold")
if ((registerValue < 0xff)) {
data[1] = (char) registerValue;
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature high threshold register set to 0x%02x, (%d C).\n",
gAddress >> 1, (char) registerValue, registerToTemperatureC(registerValue << 8));
#endif
}
} else {
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): trying to set temperature high threshold to %d C, value is too large (0x%04x < 0xff).\n",
gAddress >> 1, temperatureC, registerValue);
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Get temperature alert upper threshold.
bool BatteryGaugeLtc2943::getTemperatureHigh (int32_t *pTemperatureC)
{
bool success = false;
char data[2];
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
data[0] = 0x16; // Temperature threshold high address
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
success = true;
if (pTemperatureC) {
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
*pTemperatureC = registerToTemperatureC(((uint16_t) data[1]) << 8);
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature high threshold register reports 0x%02x (a temperature of %d C).\n",
gAddress >> 1, ((uint16_t) data[1]) << 8, registerToTemperatureC(((uint16_t) data[1]) << 8));
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Is the temperature alert upper threshold set.
bool BatteryGaugeLtc2943::isTemperatureHighSet (void)
{
bool isSet = false;
char data[2];
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
data[0] = 0x16; // Temperature threshold high address
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
if (data[1] < 0xff) {
isSet = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature high threshold register is set.\n", gAddress >> 1);
#endif
}
}
gpI2c->unlock();
}
return isSet;
}
/// Clear temperature alert upper threshold.
bool BatteryGaugeLtc2943::clearTemperatureHigh (void)
{
bool success = false;
char data[2];
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
data[0] = 0x16; // Temperature threshold high address
data[1] = 0xff; // 0xFF means no upper threshold set
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature high threshold register cleared.\n", gAddress >> 1);
#endif
}
gpI2c->unlock();
}
return success;
}
/// Set temperature alert lower threshold.
bool BatteryGaugeLtc2943::setTemperatureLow (int32_t temperatureC)
{
bool success = false;
uint16_t registerValue = temperatureCToRegister (temperatureC);
char data[2];
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
registerValue >>= 8;
// Check for overflow in conversion to the register value
if (TOLERANCE_CHECK (registerToTemperatureC(registerValue << 8), temperatureC, LTC_2943_TOLERANCE)) {
data[0] = 0x17; // Temperature threshold low address
// Only write the value if it fits (and taking into
// account the fact that 0 means "no lower threshold")
if (registerValue > 0) {
data[1] = (char) registerValue;
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature low threshold register set to 0x%02x, (%d C).\n",
gAddress >> 1, (char) registerValue, registerToTemperatureC(registerValue << 8));
#endif
}
} else {
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): trying to set temperature low threshold to %d C, value is too small (0x%04x > 0).\n",
gAddress >> 1, temperatureC, registerValue);
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// get temperature alert lower threshold.
bool BatteryGaugeLtc2943::getTemperatureLow (int32_t *pTemperatureC)
{
bool success = false;
char data[2];
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
data[0] = 0x17; // Temperature threshold low address
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
success = true;
if (pTemperatureC) {
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
*pTemperatureC = registerToTemperatureC(((uint16_t) data[1]) << 8);
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature low threshold register reports 0x%02x (a temperature of %d C).\n",
gAddress >> 1, ((uint16_t) data[1]) << 8, registerToTemperatureC(((uint16_t) data[1]) << 8));
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Is the temperature alert lower threshold set.
bool BatteryGaugeLtc2943::isTemperatureLowSet (void)
{
bool isSet = false;
char data[2];
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
data[0] = 0x17; // Temperature threshold low address
data[1] = 0;
if ((gpI2c->write(gAddress, &(data[0]), 1, true) == 0) &&
(gpI2c->read(gAddress, &(data[1]), 1) == 0)) {
if (data[1] > 0) {
isSet = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature low threshold register is set.\n", gAddress >> 1);
#endif
}
}
gpI2c->unlock();
}
return isSet;
}
/// Clear temperature alert lower threshold.
bool BatteryGaugeLtc2943::clearTemperatureLow (void)
{
bool success = false;
char data[2];
// Note that the temperature threshold is 8 bit, not 16 bits
// like all the other thresholds
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
data[0] = 0x17; // Temperature threshold low address
data[1] = 0; // 0 means no lower threshold set
if (gpI2c->write(gAddress, &(data[0]), 2) == 0) {
success = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): temperature low threshold register is cleared.\n", gAddress >> 1);
#endif
}
gpI2c->unlock();
}
return success;
}
/// Set voltage alert upper threshold.
bool BatteryGaugeLtc2943::setVoltageHigh (int32_t voltageMV)
{
bool success = false;
uint16_t registerValue = voltageMVToRegister(voltageMV);
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
// Check for overflow in conversion to the register value
if (TOLERANCE_CHECK (registerToVoltageMV(registerValue), voltageMV, LTC_2943_TOLERANCE)) {
// Only write the value if it is less than 0xffff (as
// 0xffff means no threshold set)
if (registerValue < 0xfff) {
success = setTwoBytes (0x0a, registerValue);
#ifdef DEBUG_LTC2943
if (success) {
printf("BatteryGaugeLtc2943 (I2C 0x%02x): voltage high threshold register set to 0x%04x, (%d mV).\n",
gAddress >> 1, registerValue, registerToVoltageMV(registerValue));
}
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Get voltage alert upper threshold.
bool BatteryGaugeLtc2943::getVoltageHigh (int32_t *pVoltageMV)
{
bool success = false;
uint16_t data;
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
success = getTwoBytes (0x0a, &data);
if (success && pVoltageMV) {
*pVoltageMV = registerToVoltageMV (data);
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): voltage high threshold register is 0x%04x, (%d mV).\n",
gAddress >> 1, data, registerToVoltageMV(data));
#endif
}
gpI2c->unlock();
}
return success;
}
/// Is the voltage alert upper threshold set.
bool BatteryGaugeLtc2943::isVoltageHighSet (void)
{
bool isSet = false;
uint16_t data;
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
// Default value is 0xffff, so if it is not that it is set
if (getTwoBytes (0x0a, &data) && (data != 0xffff)) {
isSet = true;
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): voltage high threshold register is set.\n", gAddress >> 1);
#endif
}
gpI2c->unlock();
}
return isSet;
}
/// Clear voltage alert upper threshold.
bool BatteryGaugeLtc2943::clearVoltageHigh (void)
{
bool success = false;
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
success = setTwoBytes (0x0a, 0xffff);
#ifdef DEBUG_LTC2943
printf("BatteryGaugeLtc2943 (I2C 0x%02x): voltage high threshold register is cleared.\n", gAddress >> 1);
#endif
gpI2c->unlock();
}
return success;
}
/// Set voltage alert lower threshold.
bool BatteryGaugeLtc2943::setVoltageLow (int32_t voltageMV)
{
bool success = false;
uint16_t registerValue = voltageMVToRegister (voltageMV);
if (gReady && (gpI2c != NULL)) {
gpI2c->lock();
// Check for overflow in conversion to the register value
if (TOLERANCE_CHECK (registerToVoltageMV(registerValue), voltageMV, LTC_2943_TOLERANCE)) {
// Only write the value if it is greater than 0 (as
// 0 means no threshold set)
if (registerValue > 0) {
success = setTwoBytes (0x0c, registerValue);
#ifdef DEBUG_LTC2943
if (success) {
printf("BatteryGaugeLtc2943 (I2C 0x%02x): voltage low threshold register set to 0x%04x, (%d mV).\n",
gAddress >> 1, registerValue, registerToVoltageMV(registerValue));
}
#endif
}
}
gpI2c->unlock();
}
return success;
}
/// Get voltage alert lower threshold.