/*!
 LTC2944: Multicell Battery Gas Gauge with Temperature, Voltage and Current Measurement

@verbatim

The LTC®2944 measures battery charge state, battery voltage,
battery current and its own temperature in portable
product applications. The wide input voltage range allows
use with multicell batteries up to 60V. A precision coulomb
counter integrates current through a sense resistor between
the battery’s positive terminal and the load or charger.
Voltage, current and temperature are measured with an
internal 14-bit No Latency ΔΣ™ ADC. The measurements
are stored in internal registers accessible via the onboard
I2C/SMBus Interface.

I2C DATA FORMAT (MSB FIRST):

Data Out:
Byte #1                                    Byte #2                     Byte #3

START  SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK  C7  C6 C5 C4 C3 C2 C1 C0 SACK D7 D6 D5 D4 D3 D2 D1 D0 SACK  STOP

Data In:
Byte #1                                    Byte #2                                    Byte #3

START  SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK  C7  C6  C5 C4 C3 C2 C1 C0 SACK  Repeat Start SA6 SA5 SA4 SA3 SA2 SA1 SA0 R SACK

Byte #4                                   Byte #5
MSB                                       LSB
D15 D14  D13  D12  D11  D10  D9 D8 MACK   D7 D6 D5 D4 D3  D2  D1  D0  MNACK  STOP

START       : I2C Start
Repeat Start: I2c Repeat Start
STOP        : I2C Stop
SAx         : I2C Address
SACK        : I2C Slave Generated Acknowledge (Active Low)
MACK        : I2C Master Generated Acknowledge (Active Low)
MNACK       : I2c Master Generated Not Acknowledge
W           : I2C Write (0)
R           : I2C Read  (1)
Cx          : Command Code
Dx          : Data Bits
X           : Don't care



Example Code:

Read charge, current, and voltage.

    adc_command = LTC2944_SENSE_MONITOR | LTC2944_AUTOMATIC_MODE; // Builds commands to set LTC2944 to automatic mode
    ack |= LTC2944_write(LTC2944_I2C_ADDRESS, LTC2944_CONTROL_REG, adc_command);   // Sets the LTC2944 to automatic mode

    resistor = .1; // Resistor Value On Demo Board

    ack |= LTC2944_read_16_bits(LTC2944_I2C_ADDRESS, LTC2944_CHARGE_MSB_REG, &charge_code);  // Reads the ADC registers that contains charge value
    charge = LTC2944_code_to_coulombs(charge_code, resistor, prescalarValue); // Calculates charge from charge code, resistor and prescalar

    ack |= LTC2944_read_16_bits(LTC2944_I2C_ADDRESS, LTC2944_CURRENT_MSB_REG, &current_code); // Reads the voltage code across sense resistor
    current = LTC2944_code_to_current(current_code, resistor); // Calculates current from current code, resistor value.

    ack |= LTC2944_read_16_bits(LTC2944_I2C_ADDRESS, LTC2944_VOLTAGE_MSB_REG, &voltage_code);   // Reads voltage voltage code
    VIN = LTC2944_VIN_code_to_voltage(voltage_code);  // Calculates VIN voltage from VIN code and lsb


@endverbatim
*/

/*! @file
    @ingroup LTC2944
    Header for LTC2944: Multicell Battery Gas Gauge with Temperature, Voltage and Current Measurement
*/


#ifndef LTC2944_H
#define LTC2944_H

#include <Wire.h>


/*!
| LTC2944 I2C Address Assignment    | Value |
| :-------------------------------- | :---: |
| LTC2944_I2C_ADDRESS               | 0xC8  |
*/

/*! @name LTC2944 I2C Address
@{ */

#define LTC2944_I2C_ADDRESS 0x64
#define LTC2944_I2C_ALERT_RESPONSE  0x0C
//! @}


/*!
| Name                                              | Value |
| :------------------------------------------------ | :---: |
| LTC2944_STATUS_REG                                | 0x00  |
| LTC2944_CONTROL_REG                               | 0x01  |
| LTC2944_ACCUM_CHARGE_MSB_REG                      | 0x02  |
| LTC2944_ACCUM_CHARGE_LSB_REG                      | 0x03  |
| LTC2944_CHARGE_THRESH_HIGH_MSB_REG                | 0x04  |
| LTC2944_CHARGE_THRESH_HIGH_LSB_REG                | 0x05  |
| LTC2944_CHARGE_THRESH_LOW_MSB_REG                 | 0x06  |
| LTC2944_CHARGE_THRESH_LOW_LSB_REG                 | 0x07  |
| LTC2944_VOLTAGE_MSB_REG                           | 0x08  |
| LTC2944_VOLTAGE_LSB_REG                           | 0x09  |
| LTC2944_VOLTAGE_THRESH_HIGH_MSB_REG               | 0x0A  |
| LTC2944_VOLTAGE_THRESH_HIGH_LSB_REG               | 0x0B  |
| LTC2944_VOLTAGE_THRESH_LOW_MSB_REG                | 0x0C  |
| LTC2944_VOLTAGE_THRESH_LOW_LSB_REG                | 0x0D  |
| LTC2944_CURRENT_MSB_REG                           | 0x0E  |
| LTC2944_CURRENT_LSB_REG                           | 0x0F  |
| LTC2944_CURRENT_THRESH_HIGH_MSB_REG               | 0x10  |
| LTC2944_CURRENT_THRESH_HIGH_LSB_REG               | 0x11  |
| LTC2944_CURRENT_THRESH_LOW_MSB_REG                | 0x12  |
| LTC2944_CURRENT_THRESH_LOW_LSB_REG                | 0x13  |
| LTC2944_TEMPERATURE_MSB_REG                       | 0x14  |
| LTC2944_TEMPERATURE_LSB_REG                       | 0x15  |
| LTC2944_TEMPERATURE_THRESH_HIGH_REG               | 0x16  |
| LTC2944_TEMPERATURE_THRESH_LOW_REG                | 0x17  |
*/

/*! @name Registers
@{ */
// Registers
#define LTC2944_STATUS_REG                          0x00
#define LTC2944_CONTROL_REG                         0x01
#define LTC2944_ACCUM_CHARGE_MSB_REG                0x02
#define LTC2944_ACCUM_CHARGE_LSB_REG                0x03
#define LTC2944_CHARGE_THRESH_HIGH_MSB_REG          0x04
#define LTC2944_CHARGE_THRESH_HIGH_LSB_REG          0x05
#define LTC2944_CHARGE_THRESH_LOW_MSB_REG           0x06
#define LTC2944_CHARGE_THRESH_LOW_LSB_REG           0x07
#define LTC2944_VOLTAGE_MSB_REG                     0x08
#define LTC2944_VOLTAGE_LSB_REG                     0x09
#define LTC2944_VOLTAGE_THRESH_HIGH_MSB_REG         0x0A
#define LTC2944_VOLTAGE_THRESH_HIGH_LSB_REG         0x0B
#define LTC2944_VOLTAGE_THRESH_LOW_MSB_REG          0x0C
#define LTC2944_VOLTAGE_THRESH_LOW_LSB_REG          0x0D
#define LTC2944_CURRENT_MSB_REG                     0x0E
#define LTC2944_CURRENT_LSB_REG                     0x0F
#define LTC2944_CURRENT_THRESH_HIGH_MSB_REG         0x10
#define LTC2944_CURRENT_THRESH_HIGH_LSB_REG         0x11
#define LTC2944_CURRENT_THRESH_LOW_MSB_REG          0x12
#define LTC2944_CURRENT_THRESH_LOW_LSB_REG          0x13
#define LTC2944_TEMPERATURE_MSB_REG                 0x14
#define LTC2944_TEMPERATURE_LSB_REG                 0x15
#define LTC2944_TEMPERATURE_THRESH_HIGH_REG         0x16
#define LTC2944_TEMPERATURE_THRESH_LOW_REG          0x17
//! @}

/*!
| Command Codes                                 | Value     |
| :-------------------------------------------- | :-------: |
| LTC2944_AUTOMATIC_MODE                        | 0xC0      |
| LTC2944_SCAN_MODE                             | 0x80      |
| LTC2944_MANUAL_MODE                           | 0x40      |
| LTC2944_SLEEP_MODE                            | 0x00      |
| LTC2944_PRESCALAR_M_1                         | 0x00      |
| LTC2944_PRESCALAR_M_4                         | 0x08      |
| LTC2944_PRESCALAR_M_16                        | 0x10      |
| LTC2944_PRESCALAR_M_64                        | 0x18      |
| LTC2944_PRESCALAR_M_256                       | 0x20      |
| LTC2944_PRESCALAR_M_1024                      | 0x28      |
| LTC2944_PRESCALAR_M_4096                      | 0x30      |
| LTC2944_PRESCALAR_M_4096_2                    | 0x31      |
| LTC2944_ALERT_MODE                            | 0x04      |
| LTC2944_CHARGE_COMPLETE_MODE                  | 0x02      |
| LTC2944_DISABLE_ALCC_PIN                      | 0x00      |
| LTC2944_SHUTDOWN_MODE                         | 0x01      |
*/

/*! @name Command Codes
@{ */
// Command Codes
#define LTC2944_AUTOMATIC_MODE                  0xC0
#define LTC2944_SCAN_MODE                       0x80
#define LTC2944_MANUAL_MODE                     0x40
#define LTC2944_SLEEP_MODE                      0x00

#define LTC2944_PRESCALAR_M_1                   0x00
#define LTC2944_PRESCALAR_M_4                   0x08
#define LTC2944_PRESCALAR_M_16                  0x10
#define LTC2944_PRESCALAR_M_64                  0x18
#define LTC2944_PRESCALAR_M_256                 0x20
#define LTC2944_PRESCALAR_M_1024                0x28
#define LTC2944_PRESCALAR_M_4096                0x30
#define LTC2944_PRESCALAR_M_4096_2              0x31

#define LTC2944_ALERT_MODE                      0x04
#define LTC2944_CHARGE_COMPLETE_MODE            0x02

#define LTC2944_DISABLE_ALCC_PIN                0x00
#define LTC2944_SHUTDOWN_MODE                   0x01

//! @}

/*! @name Conversion Constants
@{ */
const float LTC2944_CHARGE_lsb = 0.34E-3;
const float LTC2944_VOLTAGE_lsb = 4.32E-3;
const float LTC2944_CURRENT_lsb = 31.25E-6;
const float LTC2944_TEMPERATURE_lsb = 0.25;
const float LTC2944_FULLSCALE_VOLTAGE = 70.8;
const float LTC2944_FULLSCALE_CURRENT = 64E-3; // Note: 2**11*31.25e-6 = 0.064
const float LTC2944_FULLSCALE_TEMPERATURE = 510;
//! @}

//! Write an 8-bit code to the LTC2944.
//! @return The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
int8_t LTC2944_write(uint8_t i2c_address, //!< Register address for the LTC2944
                     uint8_t adc_command, //!< The "command byte" for the LTC2944
                     uint8_t code         //!< Value that will be written to the register.
                    );

//! Write a 16-bit code to the LTC2944.
//! @return The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
int8_t LTC2944_write_16_bits(uint8_t i2c_address, //!< Register address for the LTC2944
                             uint8_t adc_command, //!< The "command byte" for the LTC2944
                             uint16_t code        //!< Value that will be written to the register.
                            );


//! Reads an 8-bit adc_code from LTC2944
//! @return The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
int8_t LTC2944_read(uint8_t i2c_address, //!< Register address for the LTC2944
                    uint8_t adc_command, //!< The "command byte" for the LTC2944
                    uint8_t *adc_code    //!< Value that will be read from the register.
                   );

//! Reads a 16-bit adc_code from LTC2944
//! @return The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
int8_t LTC2944_read_16_bits(uint8_t i2c_address, //!< Register address for the LTC2944
                            uint8_t adc_command, //!< The "command byte" for the LTC2944
                            uint16_t *adc_code   //!< Value that will be read from the register.
                           );


//! Calculate the LTC2944 charge in Coulombs
//! @return Returns the Coulombs of charge in the ACR register.
float LTC2944_code_to_coulombs(uint16_t adc_code,        //!< The RAW ADC value
                               float resistor,         //!< The sense resistor value
                               uint16_t prescalar      //!< The prescalar value
                              );

//! Calculate the LTC2944 charge in mAh
//! @return Returns the Coulombs of charge in the ACR register.
float LTC2944_code_to_mAh(uint16_t adc_code,            //!< The RAW ADC value
                          float resistor,       //!< The sense resistor value
                          uint16_t prescalar    //!< The prescalar value
                         );

//! Calculate the LTC2944 SENSE+ voltage
//! @return Returns the SENSE+ Voltage in Volts
float LTC2944_code_to_voltage(uint16_t adc_code              //!< The RAW ADC value
                             );

//! Calculate the LTC2944 current with a sense resistor
//! @return Returns the current through the sense resisor
float LTC2944_code_to_current(uint16_t adc_code,                //!< The RAW ADC value
                              float resistor                   //!< The sense resistor value
                             );

//! Calculate the LTC2944 temperature
//! @return Returns the temperature in Kelvin
float LTC2944_code_to_kelvin_temperature(uint16_t adc_code           //!< The RAW ADC value
                                        );

//! Calculate the LTC2944 temperature
//! @return Returns the temperature in Celcius
float LTC2944_code_to_celcius_temperature(uint16_t adc_code          //!< The RAW ADC value
                                         );

#endif  // LTC2944_H