DAC/DAC.cpp

#include "SPI.h"
#include "DAC.h"

extern "C" 
{
#include <inttypes.h>
#include "WConstants.h"
}


#define dac_tlv5620_lsb (_ref * (_range[ch] ? 2 : 1) / _num_steps);
#define dac_tlv5618_lsb (2 * _ref / _num_steps);


DAC_TLV5620::DAC_TLV5620(unsigned char load_pin, unsigned char latch_pin) {
  unsigned char ch;
  _load_pin = load_pin;
  _latch_pin = latch_pin;
  for (ch = 0; ch < DAC_TLV5620_NUM_CHS; ch++) {
    _range[ch] = DAC_REFX2;
    _lsb[ch]   = dac_tlv5620_lsb;
  }
  digitalWrite(_load_pin,  1);
  digitalWrite(_latch_pin, 1);
  pinMode(_load_pin, OUTPUT);
  pinMode(_latch_pin, OUTPUT);
};



char DAC_TLV5620::write_data(dac_tlv5620_chs ch, dac_tlv5620_ranges range, 
                             unsigned char code) {
  unsigned char dac_data[2];
  dac_data[0] = ((ch & 0x03) << 1) | ((range & 0x01) << 0); 
  dac_data[1] = code;
  digitalWrite(_latch_pin, 1);
  digitalWrite(_load_pin,  1);
  spi.write(dac_data, 2);
  digitalWrite(_load_pin,  0);
  delayMicroseconds(10); 
  digitalWrite(_load_pin,  1);
  delayMicroseconds(10); 
  digitalWrite(_latch_pin, 0);
  delayMicroseconds(10); 
  digitalWrite(_latch_pin, 1);
  return(0);
};

char DAC_TLV5620::set_code(dac_tlv5620_chs ch, unsigned char code) { 
  return(write_data(ch, _range[ch], code));
}

void DAC_TLV5620::set_range(dac_tlv5620_chs ch, dac_tlv5620_ranges range) { 
  _range[ch] = range; 
  _lsb[ch] = dac_tlv5620_lsb;
} 


char DAC_TLV5620::set_voltage(dac_tlv5620_chs ch, double v) {
  if (v > _lsb[ch] * _fs_code - DBL_EPSILON) return(set_code(ch, _fs_code));
  if (v < DBL_EPSILON) return(set_code(ch, 0));
  return(set_code(ch, (unsigned char)(v / _lsb[ch])));
}


// ********************
// 5618
// ********************



DAC_TLV5618::DAC_TLV5618(unsigned char cs_pin, dac_tlv5618_pwrs pwr, dac_tlv5618_spds spd) {
  unsigned char ch;
  _cs_pin = cs_pin;
  _lsb = dac_tlv5618_lsb;
  _control.control_byte = pwr | spd;
  digitalWrite(_cs_pin,  1);
  pinMode(_cs_pin, OUTPUT);
};



char DAC_TLV5618::write_data(dac_tlv5618_rs rs, unsigned int code) {
  unsigned char dac_data[2];
  _control.control_byte &= DAC_TLV5618_RS_MASK;
  _control.control_byte |= rs;
  dac_data[0] = (unsigned char)(((code & 0xF00)>>8) | _control.control_byte);
  dac_data[1] = (unsigned char)(code & 0xFF);
  digitalWrite(_cs_pin, 0);
  delayMicroseconds(10); 
  spi.write(dac_data, 2);
  delayMicroseconds(10); 
  digitalWrite(_cs_pin,  1);
  return(0);
};



char DAC_TLV5618::set_voltage(dac_tlv5618_rs rs, double v) {
  if (v > _lsb * _fs_code - DBL_EPSILON) return(set_code(rs, _fs_code));
  if (v < DBL_EPSILON) return(set_code(rs, 0));
  return(set_code(rs, (unsigned int)(v / _lsb)));
}

char DAC_TLV5618::set_code(dac_tlv5618_rs rs, unsigned int code) { 
  if (code > 4095) code = 4095;
  return(write_data(rs, code));
}

void DAC_TLV5618::set_speed(dac_tlv5618_spds spd) { 
  _control.control_bits.SPD = spd ? 1 : 0;
}


void DAC_TLV5618::set_power_control(dac_tlv5618_pwrs pwr) {
  _control.control_bits.PWR = pwr ? 1 : 0;
}