LTC2496 - 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation

/*!
Linear Technology DC1011A-B Demonstration Board.
LTC2496: 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation

@verbatim

NOTES
  Setup:
    Set the terminal baud rate to 115200 and select the newline terminator.
    Equipment required is a precision voltage source and a precision
    voltmeter. No external power supply is required. Ensure all jumpers on
    the demo board are installed in their default positions from the
    factory.

  How to test Single-Ended mode:
    The voltage source should be connected to the ADC such that the negative
    lead is connected to COM. The positive lead may be connected to any
    channel input. Ensure voltage is within analog input voltage range -2.5V to
    +2.5V.

  How to test Differential Mode:
    The voltage source should be connected with positive and negative leads to
    paired channels. The voltage source negative output must also be connected to
    the COM pin in order to provide a ground-referenced voltage. Ensure voltage is
    within analog input voltage range -2.5V to +2.5V. Swapping input voltages
    results in a reversed polarity reading.

USER INPUT DATA FORMAT:
 decimal : 1024
 hex     : 0x400
 octal   : 02000  (leading 0 "zero")
 binary  : B10000000000
 float   : 1024.0


@endverbatim

http://www.linear.com/product/LTC2496

http://www.linear.com/product/LTC2496#demoboards

REVISION HISTORY
$Revision: 4049 $
$Date: 2015-09-22 17:24:56 -0700 (Tue, 22 Sep 2015) $


Copyright (c) 2014, Linear Technology Corp.(LTC)
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.

The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.  Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
*/

/*! @file
  @ingroup LTC2496
*/

#include <Arduino.h>
#include <stdint.h>
#include "Linduino.h"
#include "LT_SPI.h"
#include "UserInterface.h"
#include "QuikEval_EEPROM.h"
#include "LTC2496.h"
#include "LTC24XX_general.h"
#include <SPI.h>
#include <Wire.h>
#include "LT_I2C.h"

// Function Declaration
void print_title();                             // Print the title block
void print_prompt();                            // Prompt the user for an input command
void print_user_command(uint8_t menu);             // Display selected differential channels

uint8_t menu_1_read_single_ended();
uint8_t menu_2_read_differential();

// Global variables
static uint8_t demo_board_connected;            //!< Set to 1 if the board is connected
static float reference_voltage = 5;             //!< The reference voltage range, set to 5v through JP2 and JP3 by default

//Constants
const uint16_t MISO_TIMEOUT = 1000;       //!< The MISO timeout (ms)
// Build the command for single-ended mode
const uint8_t BUILD_COMMAND_SINGLE_ENDED[16] = {LTC2496_CH0,
    LTC2496_CH1,
    LTC2496_CH2,
    LTC2496_CH3,
    LTC2496_CH4,
    LTC2496_CH5,
    LTC2496_CH6,
    LTC2496_CH7,
    LTC2496_CH8,
    LTC2496_CH9,
    LTC2496_CH10,
    LTC2496_CH11,
    LTC2496_CH12,
    LTC2496_CH13,
    LTC2496_CH14,
    LTC2496_CH15
                                               };        //!< Builds the command for single-ended mode

// Build the command for differential mode
const uint8_t BUILD_COMMAND_DIFF[16] = { LTC2496_P0_N1,
                                       LTC2496_P2_N3,
                                       LTC2496_P4_N5,
                                       LTC2496_P6_N7,
                                       LTC2496_P8_N9,
                                       LTC2496_P10_N11,
                                       LTC2496_P12_N13,
                                       LTC2496_P14_N15,
                                       LTC2496_P1_N0,
                                       LTC2496_P3_N2,
                                       LTC2496_P5_N4,
                                       LTC2496_P7_N6,
                                       LTC2496_P9_N8,
                                       LTC2496_P11_N10,
                                       LTC2496_P13_N12,
                                       LTC2496_P15_N14
                                       };


//! Initialize Linduino
void setup()
// Setup the program
{
  char demo_name[] = "DC1011";   // Demo Board Name stored in QuikEval EEPROM

  quikeval_SPI_init();          // Configure the spi port for 4MHz SCK
  quikeval_SPI_connect();       // Connect SPI to main data port
  quikeval_I2C_init();              // Configure the EEPROM I2C port for 100kHz
  Serial.begin(115200);         // Initialize the serial port to the PC
  print_title();
  demo_board_connected = discover_demo_board(demo_name);
  if (demo_board_connected)
  {
    print_prompt();
  }
}

//! Repeats Linduino loop
void loop()
{
  uint8_t user_command;             // The user input command
  uint8_t ack = 0;
  if (demo_board_connected)
  {
    if (Serial.available())         // Check for user input
    {
      user_command = read_int();    // Read the user command
      if (user_command == 'm');
      else
        Serial.println(user_command);
      delay(50);                    // Allow the print to finish
      switch (user_command)
      {
        case 1:
          ack |= menu_1_read_single_ended();
          break;
        case 2:
          ack |= menu_2_read_differential();
          break;
        default:
          Serial.println("Incorrect Option");
          break;
      }
      if (ack)
        Serial.println(F("***** SPI ERROR *****"));
      Serial.println(F("*****************************************************************"));
      print_prompt();
    }
  }
}

//Function Definitions

//! Prints the title block when program first starts.
void print_title()
{
  Serial.println();
  Serial.println(F("*****************************************************************"));
  Serial.println(F("* DC1011A-B Demonstration Program                               *"));
  Serial.println(F("*                                                               *"));
  Serial.println(F("* This program demonstrates how to send data and receive data   *"));
  Serial.println(F("* from the 24-bit delta-sigma ADC.                              *"));
  Serial.println(F("*                                                               *"));
  Serial.println(F("*                                                               *"));
  Serial.println(F("* Set the baud rate to 115200 select the newline terminator.    *"));
  Serial.println(F("*                                                               *"));
  Serial.println(F("*****************************************************************"));
}

//! Prints main menu.
void print_prompt()
{

  Serial.println(F("1-Read Single-Ended"));
  Serial.println(F("2-Read Differential"));
  Serial.println();
  Serial.print(F("Enter a command:"));
}

//! read from ADC single-ended
//! @return 0 if successful, 1 if failure
//! @return 0 when m is entered into menu, 1 if timeout for EOC
uint8_t menu_1_read_single_ended()
{
  uint8_t  adc_command;  // The LTC2496 command byte
  int16_t user_command;  // The user input command
  int32_t adc_code=0;    // The LTC2496 code
  float adc_voltage;     // The LTC2496 voltage

  while (1)
  {
    Serial.print(F("*************************\n\n"));      // Display single-ended menu
    Serial.print(F("0-CH0  8-CH8\n"));
    Serial.print(F("1-CH1  9-CH9\n"));
    Serial.print(F("2-CH2  10-CH10\n"));
    Serial.print(F("3-CH3  11-CH11\n"));
    Serial.print(F("4-CH4  12-CH12\n"));
    Serial.print(F("5-CH5  13-CH13\n"));
    Serial.print(F("6-CH6  14-CH14\n"));
    Serial.print(F("7-CH7  15-CH15\n"));
    Serial.print(F("16-ALL\n"));
    Serial.print(F("m-Main Menu\n"));
    Serial.print(F("\nEnter a Command: "));
    user_command = read_int();                              // Read the single command
    if (user_command == 'm')
      return(0);
    else
      Serial.println(user_command);
    Serial.println();

    if (user_command == 16)
    {
      Serial.print(F("ALL\n"));
      adc_command = LTC2496_ENABLE | BUILD_COMMAND_SINGLE_ENDED[0];          // Build ADC command for channel 0

      if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))     // Check for EOC
        return(1);
      LTC2496_read(LTC2496_CS, adc_command, &adc_code);     // Throws out last reading

      for (int8_t x = 0; x < 15; x++)
      {
        adc_command = LTC2496_ENABLE | BUILD_COMMAND_SINGLE_ENDED[(x + 1) % 16]; // Read all channels in single-ended mode
        if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))       // Check for EOC
          return(1);
        LTC2496_read(LTC2496_CS, adc_command, &adc_code);
        adc_voltage = LTC2496_code_to_voltage(adc_code, reference_voltage);
        Serial.print(F("  ****"));
        Serial.print(F("CH"));
        Serial.print(x);
        Serial.print(F(": "));
        Serial.print(adc_voltage, 4);
        Serial.print(F("V\n"));
      }
    }
    else if (user_command<16 && user_command >=0)                           // Read selected channel
    {
      adc_command = LTC2496_ENABLE | BUILD_COMMAND_SINGLE_ENDED[user_command];
      Serial.print(F("\nADC Command: B"));
      Serial.println(adc_command, BIN);
      if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))     // Check for EOC
        return(1);
      LTC2496_read(LTC2496_CS, adc_command, &adc_code);     // Throws out last reading
      if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))     // Check for EOC
        return(1);
      LTC2496_read(LTC2496_CS, adc_command, &adc_code);
      Serial.print(F("Received Code: 0x"));
      Serial.println(adc_code, HEX);
      adc_voltage = LTC2496_code_to_voltage(adc_code, reference_voltage);
      Serial.print(F("  ****"));
      Serial.print(F("CH"));
      Serial.print(user_command);
      Serial.print(F(": "));
      Serial.print(adc_voltage, 4);
      Serial.print(F("V\n"));
    }
  }
}

//! Read channels in differential mode
//! @return 0 when m is entered into menu, 1 if timeout for EOC
uint8_t menu_2_read_differential()
{
  int8_t y;             // Offset into differential channel array to select polarity
  uint8_t  adc_command; // The LTC2496 command byte
  int16_t user_command; // The user input command
  int32_t adc_code=1;    // The LTC2496 code
  float adc_voltage;    // The LTC2496 voltage

  while (1)
  {
    // Display differential menu
    Serial.print(F("\n*************************\n\n"));
    Serial.print(F("0-0P-1N     8-1P-0N\n"));
    Serial.print(F("1-2P-3N     9-3P-2N\n"));
    Serial.print(F("2-4P-5N     10-5P-4N\n"));
    Serial.print(F("3-6P-7N     11-7P-6N\n"));
    Serial.print(F("4-8P-9N     12-9P-8N\n"));
    Serial.print(F("5-10P-11N   13-11P-10N\n"));
    Serial.print(F("6-12P_13N   14-13P-12N\n"));
    Serial.print(F("7-14P-15N   15-15P-14N\n"));
    Serial.print(F("16-ALL Even_P-Odd_N\n"));
    Serial.print(F("17-ALL Odd_P-Even_N\n"));
    Serial.print(F("m-Main Menu\n"));
    Serial.print(F("\nEnter a Command: "));
    user_command = read_int();
    if (user_command == 'm')
      return(0);
    Serial.println(user_command);
    Serial.println();

    if ((user_command == 16) || (user_command == 17))
    {
      if (user_command == 16)
      {
        Serial.print(F("ALL Even_P-Odd_N\n"));              // Cycles through options 0-7
        y = 0;
      }
      if (user_command == 17)
      {
        Serial.print(F("ALL Odd_P-Even_N\n"));              // Cycles through options 8-15
        y = 8;
      }
      adc_command = LTC2496_ENABLE | BUILD_COMMAND_DIFF[y];                  // Set up first channel
      if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))     // check for EOC
        return(1);
      LTC2496_read(LTC2496_CS, adc_command, &adc_code);     // Throws out last reading
      for (int8_t x = 0; x <= 7; x++)                       // Read all channels. All even channels are positive and odd channels are negative
      {
        adc_command = LTC2496_ENABLE | BUILD_COMMAND_DIFF[((x+1) % 8) + y];
        if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))   // Check for EOC
          return(1);
        LTC2496_read(LTC2496_CS, adc_command, &adc_code);
        adc_voltage = LTC2496_code_to_voltage(adc_code, reference_voltage);
        Serial.println();
        Serial.print(F("**** "));
        print_user_command(x + y);
        Serial.print(F(": "));
        Serial.print(adc_voltage, 4);
        Serial.print(F("V\n"));
      }
    }
    else                                                    // Read selected channels
    {
      // Reads and displays a selected channel
      adc_command = LTC2496_ENABLE | BUILD_COMMAND_DIFF[user_command];
      Serial.print(F("ADC Command: 0b"));
      Serial.println(adc_command, BIN);
      if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))     // Check for EOC
        return(1);
      LTC2496_read(LTC2496_CS, adc_command, &adc_code);     // Throws out last reading
      if (LTC2496_EOC_timeout(LTC2496_CS, MISO_TIMEOUT))     // Check for EOC
        return(1);
      LTC2496_read(LTC2496_CS, adc_command, &adc_code);
      Serial.print(F("Received Code: 0x"));
      Serial.println(adc_code, HEX);
      adc_voltage = LTC2496_code_to_voltage(adc_code, reference_voltage);
      Serial.println();
      Serial.print(F("**** "));
      Serial.print(F("CH"));
      print_user_command(user_command);
      Serial.print(F(": "));
      Serial.print(adc_voltage, 4);
      Serial.print(F("V"));
      Serial.println();
    }
  }
}

//! Display selected differential channels. Displaying Single-Ended channels is
//! straightforward; not so with differential because the inputs can take either polarity.
void print_user_command(uint8_t menu) //!< the selected channels
{
  switch (menu)
  {
    case 0:
      Serial.print("0P-1N");
      break;
    case 1:
      Serial.print("2P-3N");
      break;
    case 2:
      Serial.print("4P-5N");
      break;
    case 3:
      Serial.print("6P-7N");
      break;
    case 4:
      Serial.print("8P-9N");
      break;
    case 5:
      Serial.print("10P-11N");
      break;
    case 6:
      Serial.print("12P-13N");
      break;
    case 7:
      Serial.print("14P-15N");
      break;
    case 8:
      Serial.print("1P-0N");
      break;
    case 9:
      Serial.print("3P-2N");
      break;
    case 10:
      Serial.print("5P-4N");
      break;
    case 11:
      Serial.print("7P-6N");
      break;
    case 12:
      Serial.print("9P-8N");
      break;
    case 13:
      Serial.print("11P-10N");
      break;
    case 14:
      Serial.print("13P-12N");
      break;
    case 15:
      Serial.print("15P-14N");
      break;
  }
  Serial.print(": ");
}

/*!
LTC2496: 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation

@verbatim

The LTC2496 is a 16-channel (8-differential) 16-bit No Latency ΔΣ ADC with Easy
Drive technology. The patented sampling scheme eliminates dynamic input current
errors and the shortcomings of on-chip buffering through automatic cancellation
of differential input current. This allows large external source impedances,
and rail-to-rail input signals to be directly digitized while maintaining
exceptional DC accuracy.

The LTC2496 includes an integrated oscillator. This device can be configured to
measure an external signal (from combinations of 16 analog input channels
operating in single ended or differential modes). It automatically rejects
line frequencies of 50Hz and 60Hz, simultaneously.

SPI DATA FORMAT (MSB First):

            Byte #1                            Byte #2                           Byte #3

Data Out :  !EOC DMY SIG MSB D15 D14 D13 D12   D11 D10 D9  D8  D7  D6  D5  D4    D3  D2  D1  D0  -   -   -   -
Data In  :  1    0   EN  SGL OS  S2  S1  S0    X   X   X   X   X   X   X   X     X   X   X   X   X   X   X   X

!EOC : End of Conversion Bit (Active Low)
DMY  : Dummy Bit (Always 0)
SIG  : Sign Bit (1-data positive, 0-data negative)
MSB  : Most Significant Bit (Provides under range and over range indication)
Dx   : Data Bits
EN   : Enable Bit (0-keep previous mode, 1-change mode)
SGL  : Enable Single-Ended Bit (0-differential, 1-single-ended)
OS   : ODD/Sign Bit
Sx   : Address Select Bit

Command Byte
1    0    EN   SGL  OS   S2   S1   S0   Comments
1    0    0    X    X    X    X    X    Keep Previous Mode
1    0    1    0    X    X    X    X    Differential Mode
1    0    1    1    X    X    X    X    Single-Ended Mode


Example Code:

Read Channel 0 in Single-Ended mode

    uint16_t miso_timeout = 1000;
    adc_command = LTC2496_CH0;                          // Build ADC command for channel 0

    if(LTC2496_EOC_timeout(LTC2496_CS, miso_timeout))    // Check for EOC
        return(1);
    LTC2496_read(LTC2496_CS, adc_command, &adc_code);   // Throws out last reading

    if(LTC2496_EOC_timeout(LTC2496_CS, miso_timeout))    // Check for EOC
        return(1);
    LTC2496_read(LTC2496_CS, adc_command, &adc_code);   // Obtains the current reading and stores to adc_code variable

    // Convert adc_code to voltage
    adc_voltage = LTC2496_code_to_voltage(adc_code, LTC2496_lsb , LTC2496_offset_code);

@endverbatim

http://www.linear.com/product/LTC2496

http://www.linear.com/product/LTC2496#demoboards

REVISION HISTORY
$Revision: 4049 $
$Date: 2015-09-22 17:24:56 -0700 (Tue, 22 Sep 2015) $


Copyright (c) 2014, Linear Technology Corp.(LTC)
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.

The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.  Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
*/

/*! @file
  @ingroup LTC2496
  Header for LTC2496 LTC2496: 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation
*/

#ifndef LTC2496_H
#define LTC2496_H

//! define the SPI CS pin
#ifndef LTC2496_CS
#define LTC2496_CS QUIKEVAL_CS
#endif

//! @name LTC2496 Command Constraints
//!@{
//! Command Constants.
#define LTC2496_DISABLE     0x80
#define LTC2496_ENABLE      0xA0


//!Channel Selection OR with ENABLE or select DISABLE to use previous selection
/*!
//!Use table to select address
/*!
|LTC2496 Channel Selection     | Value    |
| :--------------------------: | :------: |
| LTC2496_P0_N1                |    0x00  |
| LTC2496_P1_N0                |    0x08  |
|                              |          |
| LTC2496_P2_N3                |    0x01  |
| LTC2496_P3_N2                |    0x09  |
|                              |          |
| LTC2496_P4_N5                |    0x02  |
| LTC2496_P5_N4                |    0x0A  |
|                              |          |
| LTC2496_P6_N7                |    0x03  |
| LTC2496_P7_N6                |    0x0B  |
|                              |          |
| LTC2496_P8_N9                |    0x04  |
| LTC2496_P9_N8                |    0x0C  |
|                              |          |
| LTC2496_P10_N11              |    0x05  |
| LTC2496_P11_N10              |    0x0D  |
|                              |          |
| LTC2496_P12_N13              |    0x06  |
| LTC2496_P13_N12              |    0x0E  |
|                              |          |
| LTC2496_P14_N15              |    0x07  |
| LTC2496_P15_N14              |    0x0F  |
*/
/*! @name LTC2496 Differential Channel Selection
@{*/

#define LTC2496_P0_N1          0x00
#define LTC2496_P1_N0          0x08

#define LTC2496_P2_N3          0x01
#define LTC2496_P3_N2          0x09

#define LTC2496_P4_N5          0x02
#define LTC2496_P5_N4          0x0A

#define LTC2496_P6_N7          0x03
#define LTC2496_P7_N6          0x0B

#define LTC2496_P8_N9          0x04
#define LTC2496_P9_N8          0x0C

#define LTC2496_P10_N11        0x05
#define LTC2496_P11_N10        0x0D

#define LTC2496_P12_N13        0x06
#define LTC2496_P13_N12        0x0E

#define LTC2496_P14_N15        0x07
#define LTC2496_P15_N14        0x0F

/*!
|LTC2496 Channel Selection     | Value    |
| :--------------------------: | :------: |
| LTC2496_CH0                  |  0x10    |
| LTC2496_CH1                  |  0x18    |
| LTC2496_CH2                  |  0x11    |
| LTC2496_CH3                  |  0x19    |
| LTC2496_CH4                  |  0x12    |
| LTC2496_CH5                  |  0x1A    |
| LTC2496_CH6                  |  0x13    |
| LTC2496_CH7                  |  0x1B    |
| LTC2496_CH8                  |  0x14    |
| LTC2496_CH9                  |  0x1C    |
| LTC2496_CH10                 |  0x15    |
| LTC2496_CH11                 |  0x1D    |
| LTC2496_CH12                 |  0x16    |
| LTC2496_CH13                 |  0x1E    |
| LTC2496_CH14                 |  0x17    |
| LTC2496_CH15                 |  0x1F    |
*/
/*! @name LTC2496 Single-Ended Channel Selection
@{ */

#define LTC2496_CH0            0x10
#define LTC2496_CH1            0x18
#define LTC2496_CH2            0x11
#define LTC2496_CH3            0x19
#define LTC2496_CH4            0x12
#define LTC2496_CH5            0x1A
#define LTC2496_CH6            0x13
#define LTC2496_CH7            0x1B
#define LTC2496_CH8            0x14
#define LTC2496_CH9            0x1C
#define LTC2496_CH10           0x15
#define LTC2496_CH11           0x1D
#define LTC2496_CH12           0x16
#define LTC2496_CH13           0x1E
#define LTC2496_CH14           0x17
#define LTC2496_CH15           0x1F


//! Checks for EOC with a specified timeout
//! @return Returns 0=successful, 1=unsuccessful (exceeded timeout)
int8_t LTC2496_EOC_timeout(uint8_t cs,            //!< Chip Select pin
                           uint16_t miso_timeout  //!< Timeout (in millisends)
                          );

//! Read LTC2496 result, program configuration for next conversion
// Example - read channel external input with 60Hz rejection and 2X enabled.
// adc_command = LTC2496_ENABLE|LTC2496_P0_N1;
//! @return void
void LTC2496_read(uint8_t cs,           //!< Chip Select pin
                  uint8_t adc_command,  //!< Command byte
                  int32_t *adc_code     //!< Returns raw 32-bit code read from ADC
                 );


//! Calculates the LTC2496 input voltage
//! @return Calculated voltage
float LTC2496_code_to_voltage(int32_t adc_code,   //!< Raw ADC code
                              float vref          //!< the reference voltage to the ADC
                             );
#endif

/*!
LTC2496: 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation

@verbatim

The LTC2496 is a 16-channel (8-differential) 16-bit No Latency ΔΣ ADC with Easy
Drive technology. The patented sampling scheme eliminates dynamic input current
errors and the shortcomings of on-chip buffering through automatic cancellation
of differential input current. This allows large external source impedances,
and rail-to-rail input signals to be directly digitized while maintaining
exceptional DC accuracy.

The LTC2496 includes an integrated oscillator. This device can be configured to
measure an external signal (from combinations of 16 analog input channels
operating in single ended or differential modes). It automatically rejects
line frequencies of 50Hz and 60Hz, simultaneously.

@endverbatim

http://www.linear.com/product/LTC2496

http://www.linear.com/product/LTC2496#demoboards

REVISION HISTORY
$Revision: 4049 $
$Date: 2015-09-22 17:24:56 -0700 (Tue, 22 Sep 2015) $


Copyright (c) 2014, Linear Technology Corp.(LTC)
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.

The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.  Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
*/

//! @defgroup LTC2496 LTC2496: 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation

/*! @file
  @ingroup LTC2496
  Library for LTC2496 LTC2496: 16-Bit 8-/16-Channel Delta Sigma ADC with Easy Drive Input Current Cancellation
*/

#include <stdint.h>
#include <Arduino.h>
#include "Linduino.h"
#include "LT_SPI.h"
#include "LTC2496.h"
#include "LTC24XX_general.h"
#include <SPI.h>

// Checks for EOC with a specified timeout
int8_t LTC2496_EOC_timeout(uint8_t cs, uint16_t miso_timeout)
{

  return LTC24XX_EOC_timeout(cs,miso_timeout);
}

// reads the LTC2496
void LTC2496_read(uint8_t cs, uint8_t adc_command, int32_t *adc_code)
{

  LTC24XX_SPI_8bit_command_24bit_data(cs, adc_command, adc_code);
}


float LTC2496_code_to_voltage(int32_t adc_code, float vref)
{

  return(LTC24XX_diff_code_to_voltage(adc_code,vref));
}