/*!
LTC2758: Dual Serial 18-Bit SoftSpan IOUT DAC

@verbatim

The LTC2758 is a dual, current-output, serial-input precision multiplying DAC
with selectable output ranges. Ranges can either be programmed in software for
maximum flexibility (each of the DACs can be programmed to any one of six output
ranges) or hardwired through pin-strapping. Two unipolar ranges are available
(0V to 5V and 0V to 10V), and four bipolar ranges (±2.5V, ±5V, ±10V and –2.5V
to 7.5V). These ranges are obtained when an external precision 5V reference is
used. The output ranges for other reference voltages are easy to calculate by
observing that each range is a multiple of the external reference voltage. The
ranges can then be expressed: 0 to 1×, 0 to 2×, ±0.5×, ±1×, ±2×, and –0.5× to 1.5×.

@endverbatim

http://www.linear.com/product/LTC2758

http://www.linear.com/product/LTC2758#demoboards


Copyright 2018(c) Analog Devices, Inc.

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   of one or more patent holders.  This license does not release you
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THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
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*/

//! @ingroup Digital_to_Analog_Converters
//! @{
//! @defgroup LTC2758 LTC2758: Dual Serial 18-Bit SoftSpan IOUT DAC
//! @}

/*! @file
    @ingroup LTC2758
    Library for LTC2758 Dual Serial 18-Bit SoftSpan IOUT DAC
*/

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

// Transmits 32 bit input stream: 4-bit command + 4-bit don't-care + 18-bit data + 6 don't care
void LTC2758_write(uint8_t cs, uint8_t dac_command, uint8_t dac_address, uint32_t data)
{
  output_low(cs);
  spi_write(dac_command|dac_address);
  spi_write((uint8_t)((data >> 10) & 0xFF));  // D17:D10
  spi_write((uint8_t)((data >> 2) & 0xFF));     // D9:D2
  spi_write((uint8_t)((data << 6) & 0xFF));     // D1:D0
  output_high(cs);
}

// Calculate the LTC2758 DAC output voltage given the DAC code and and the minimum / maximum
// outputs for a given softspan range.
float LTC2758_code_to_voltage(uint32_t dac_code, float min_output, float max_output)
{
  float dac_voltage;
  dac_voltage = (((float) dac_code / 262143.0) * (max_output - min_output)) + min_output;            // Calculate the dac_voltage
  return (dac_voltage);
}
// Calculate a LTC2758 DAC code given the desired output voltage and the minimum / maximum
// outputs for a given softspan range.
uint32_t LTC2758_voltage_to_code(float dac_voltage, float min_output, float max_output)
{
  uint32_t dac_code;
  float float_code;
  float_code = 262143.0 * (dac_voltage - min_output) / (max_output - min_output);                    // Calculate the DAC code
  float_code = (float_code > (floor(float_code) + 0.5)) ? ceil(float_code) : floor(float_code);     // Round
  if (float_code < 0.0) float_code = 0.0;
  if (float_code > 262143.0) float_code = 262143.0;
  dac_code = (uint32_t) (float_code);                                                               // Convert to unsigned integer
  return (dac_code);
}