Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board
DC1678A.ino
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1 /*!
2 Linear Technology DC1678A Demonstration Board.
3 LTC2654: Quad SPI 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference.
4 
5 @verbatim
6 NOTES
7  Setup:
8  Set the terminal baud rate to 115200 and select the newline terminator.
9  The program displays calculated voltages which are based on the voltage
10  of the reference used, be it internal or external. A precision voltmeter
11  is needed to verify the actual measured voltages against the calculated
12  voltage displayed. If an external reference is used, a precision voltage
13  source is required to apply the external reference voltage. A
14  precision voltmeter is also required to measure the external reference
15  voltage. No external power supply is required. Any assembly option
16  may be used: DC1678A-A, DC1678A-B, DC1678A-C, DC1678A-D.
17 
18 
19  Explanation of Commands:
20  1- Select DAC: Select one of four DACs to test : A, B, C, D.
21 
22  2- Write to DAC input register: Value is stored in the DAC for updating
23  later, allowing multiple channels to be updated at once, either
24  through a software "Update All" command or by asserting the LDAC# pin.
25  User will be prompted to enter either a code in hex or decimal, or a
26  voltage. If a voltage is entered, a code will be calculated based on
27  the active scaling and reference parameters - ideal values if no
28  calibration was ever stored.
29 
30  3- Write and Update: Similar to item 1, but DAC is updated immediately.
31 
32  4- Update DAC: Copies the value from the input register into the DAC
33  Register. Note that a "write and update" command writes the code to
34  BOTH the input register and DAC register, so subsequent "update"
35  commands will simply re-copy the same data (no change in output.)
36 
37  5- Power Down DAC: Disable DAC output. Power supply current is reduced.
38  DAC code present in DAC registers at time of shutdown are preserved.
39 
40  6- Set reference mode, either internal or external: Selecting external
41  mode prompts for the external reference voltage, which is used directly
42  if no individual DAC calibration is stored. The selection and entered
43  voltage are stored to EEPROM so it is persistent across reset / power cycles.
44 
45  7- Calibrate DAC: Use a precision voltmeter to obtain and enter VOUT
46  readings taken with different DAC codes. Set reference mode FIRST,
47  as values are stored separately for internal and external reference
48  mode. Entries are used to calculate the closest code to send to the
49  DAC to achieve an entered voltage.
50 
51  8- Enable / Disable calibration: Switch between stored calibration
52  values and defaults. Calibration parameters are stored separately for
53  internal and external reference modes. Ideal calibration will be used
54  if the calibration parameter valid key is not set.
55 
56 USER INPUT DATA FORMAT:
57  decimal : 1024
58  hex : 0x400
59  octal : 02000 (leading 0 "zero")
60  binary : B10000000000
61  float : 1024.0
62 
63 @endverbatim
64 
65 http://www.linear.com/product/LTC2654
66 
67 http://www.linear.com/product/LTC2654#demoboards
68 
69 
70 Copyright 2018(c) Analog Devices, Inc.
71 
72 All rights reserved.
73 
74 Redistribution and use in source and binary forms, with or without
75 modification, are permitted provided that the following conditions are met:
76  - Redistributions of source code must retain the above copyright
77  notice, this list of conditions and the following disclaimer.
78  - Redistributions in binary form must reproduce the above copyright
79  notice, this list of conditions and the following disclaimer in
80  the documentation and/or other materials provided with the
81  distribution.
82  - Neither the name of Analog Devices, Inc. nor the names of its
83  contributors may be used to endorse or promote products derived
84  from this software without specific prior written permission.
85  - The use of this software may or may not infringe the patent rights
86  of one or more patent holders. This license does not release you
87  from the requirement that you obtain separate licenses from these
88  patent holders to use this software.
89  - Use of the software either in source or binary form, must be run
90  on or directly connected to an Analog Devices Inc. component.
91 
92 THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
93 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
94 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
95 IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
96 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
97 LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
98 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
99 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
100 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
101 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
102  */
103 
104 /*! @file
105  @ingroup LTC2654
106 */
107 
108 #include <Arduino.h>
109 #include <stdint.h>
110 #include "Linduino.h"
111 #include "LT_SPI.h"
112 #include "UserInterface.h"
113 #include "LT_I2C.h"
114 #include "QuikEval_EEPROM.h"
115 #include "LTC2654.h"
116 #include <SPI.h>
117 #include <Wire.h>
118 
119 #define EEPROM_CAL_KEY_INT 0x5678 //!< Calibration associated with internal reference
120 #define EEPROM_CAL_KEY_EXT 0x9ABC //!< Calibration associated with external reference
121 
122 // DAC Reference State
123 // Could have been zero or 1, this allows you to use the
124 // variable "reference_mode" as the command argument to a write
125 #define REF_INTERNAL LTC2654_CMD_INTERNAL_REFERENCE //!< Stored reference state is Internal
126 #define REF_EXTERNAL LTC2654_CMD_EXTERNAL_REFERENCE //!< Stored reference state is External
127 
128 // EEPROM memory locations
129 #define STORED_REF_STATE_BASE EEPROM_CAL_STATUS_ADDRESS //!< Base address of the stored reference state
130 #define INT_CAL_VALID_BASE STORED_REF_STATE_BASE + 2 //!< Base address of the "internal ref calibration valid" flag
131 #define INT_CAL_PARAMS_BASE INT_CAL_VALID_BASE + 2 //!< Base address of the internal ref calibration parameters
132 #define EXT_CAL_VALID_BASE INT_CAL_PARAMS_BASE + 32 //!< Base address of the "external ref calibration valid" flag
133 #define EXT_CAL_PARAMS_BASE EXT_CAL_VALID_BASE + 2 //!< Base address of the external ref calibration parameters
134 #define EXT_REF_V_BASE EXT_CAL_PARAMS_BASE + 32 //!< Base address of the stored external reference voltage
135 
136 // Function Declaration
137 int8_t restore_calibration(); // Read the DAC calibration from EEPROM, Return 1 if successful, 0 if not
138 void store_calibration(); // Store the DAC calibration to the EEPROM
139 void print_title(); // Print the title block
140 void print_prompt(int16_t selected_dac); // Prompt the user for an input command
141 int16_t prompt_voltage_or_code();
142 uint16_t get_voltage(float LTC2654_lsb, int16_t LTC2654_offset);
143 uint16_t get_code();
144 void calibrate_dac(uint8_t index); // Calibrate the selected DAC using a voltmeter. The routine does a linear curve fit given two data points.
145 
146 void menu_1_select_dac(int16_t *selected_dac);
147 void menu_2_write_to_input_register(int16_t selected_dac);
148 void menu_3_write_and_update_dac(int16_t selected_dac);
149 void menu_4_update_power_up_dac(int16_t selected_dac);
150 void menu_5_power_down_dac(int16_t selected_dac);
151 void menu_6_set_reference_mode(); // Int, ext, if ext, prompt for voltage
152 void menu_7_calibrate_dacs();
154 
155 // Global variables
156 static uint8_t demo_board_connected; //!< Set to 1 if the board is connected
157 static uint8_t shift_count = 0; //!< The data align shift count. For 16-bit=0, for 12-bits=4
158 static uint8_t reference_mode; //!< Tells whether to set internal or external reference
159 
160 // Global calibration variables
161 static float reference_voltage; //!< Reference voltage, either internal or external
162 static int16_t LTC2654_offset[5]; //!< DAC offset - index 4 for "all DACs"
163 static float LTC2654_lsb[5]; //!< The LTC2654 lsb - index 4 for "all DACs"
164 
165 // Constants
166 
167 //! Lookup table for DAC address. Allows the "All DACs" address to be indexed right after DAC D in loops.
168 //! This technique is very useful for devices with non-monotonic channel addresses.
169 const uint8_t address_map[5] = {LTC2654_DAC_A, LTC2654_DAC_B, LTC2654_DAC_C, LTC2654_DAC_D, LTC2654_DAC_ALL}; //!< Map entered option 0..2 to DAC address
170 
171 //! Used to keep track to print voltage or print code
172 enum
173 {
174  PROMPT_VOLTAGE = 0, /**< 0 */
175  PROMPT_CODE = 1 /**< 1 */
176 };
177 
178 //! Initialize Linduino
179 void setup()
180 // Setup the program
181 {
182  char demo_name[] = "DC1678"; // Demo Board Name stored in QuikEval EEPROM
183  quikeval_SPI_init(); // Configure the spi port for 4MHz SCK
184  quikeval_SPI_connect(); // Connect SPI to main data port
185  quikeval_I2C_init(); // Configure the EEPROM I2C port for 100kHz
186  Serial.begin(115200); // Initialize the serial port to the PC
187  print_title();
190  {
192  print_prompt(0);
193  }
194 }
195 
196 //! Repeats Linduino loop
197 void loop()
198 {
199  int16_t user_command;
200  static int16_t selected_dac = 0; // The selected DAC to be updated (0=A, 1=B ... 5=All). Initialized to "A".
201  // The main control loop
202  if (demo_board_connected) // Do nothing if the demo board is not connected
203  {
204  if (Serial.available()) // Check for user input
205  {
206  user_command = read_int(); // Read the user command
207  Serial.println(user_command);
208  Serial.flush();
209  switch (user_command)
210  {
211  case 1:
212  menu_1_select_dac(&selected_dac);
213  break;
214  case 2:
215  menu_2_write_to_input_register(selected_dac);
216  break;
217  case 3:
218  menu_3_write_and_update_dac(selected_dac);
219  break;
220  case 4:
221  menu_4_update_power_up_dac(selected_dac);
222  break;
223  case 5:
224  menu_5_power_down_dac(selected_dac);
225  break;
226  case 6:
227  menu_6_set_reference_mode(); // Int, ext, if ext, prompt for voltage
229  break;
230  case 7:
233  break;
234  case 8:
237  break;
238  default:
239  Serial.println("Incorrect Option");
240  break;
241  }
242  Serial.println("\n*****************************************************************");
243  print_prompt(selected_dac);
244  }
245  }
246 }
247 
248 // Function Definitions
249 
250 //! Select which DAC to operate on
251 void menu_1_select_dac(int16_t *selected_dac)
252 {
253  // Select a DAC to operate on
254  Serial.print("Select DAC to operate on (0=A, 1=B, 2=C, 3=D, 4=All)");
255  *selected_dac = read_int();
256  if (*selected_dac == 4)
257  Serial.println("All");
258  else
259  Serial.println(*selected_dac);
260 }
261 
262 //! Write data to input register, but do not update DAC output
263 void menu_2_write_to_input_register(int16_t selected_dac)
264 {
265  uint16_t dac_code;
266 
268  dac_code = get_voltage(LTC2654_lsb[selected_dac], LTC2654_offset[selected_dac]);
269  else
270  dac_code = get_code();
271 
272  LTC2654_write(LTC2654_CS, LTC2654_CMD_WRITE, address_map[selected_dac], dac_code << shift_count);
273 }
274 
275 //!Write data to DAC register (which updates output immediately)
276 void menu_3_write_and_update_dac(int16_t selected_dac)
277 {
278  uint16_t dac_code;
279 
281  dac_code = get_voltage(LTC2654_lsb[selected_dac], LTC2654_offset[selected_dac]);
282  else
283  dac_code = get_code();
284 
286 }
287 
288 //! Update DAC with data that is stored in input register, power up if sleeping
289 void menu_4_update_power_up_dac(int16_t selected_dac)
290 {
291  // Update DAC
292  LTC2654_write(LTC2654_CS,LTC2654_CMD_UPDATE, address_map[selected_dac], 0x0000);
293 }
294 
295 //! Power down DAC
296 void menu_5_power_down_dac(int16_t selected_dac)
297 {
298  // Power down DAC
300 }
301 
302 //! Set reference mode and store to EEPROM
303 void menu_6_set_reference_mode(void) // int, ext, if ext, prompt for voltage
304 {
305  int16_t user_input;
306  Serial.println("Select reference mode - 0 for Internal, 1 for External");
307  user_input = read_int();
308  if (user_input == 1)
309  {
311  Serial.println("External reference mode; enter external reference voltage");
313  Serial.print(reference_voltage, 5);
314  Serial.println("V");
316  }
317  else
318  {
320  Serial.println("Internal reference mode selected");
321  }
322  Serial.println("Writing reference mode to EEPROM\n\n");
324 }
325 
326 //! Calibrate all DACs by measuring two known outputs
328 {
329  // Calibrate the DACs using a multimeter
330  uint8_t i;
331  for (i = 0; i < 4; i++)
332  {
333  calibrate_dac(i); // Run calibration routine
334  }
336 }
337 
338 //! Enable / Disable calibration. Use with caution - behavior is undefined if you enable calibration and an actual
339 //! calibration cycle has not been performed.
341 {
342  int16_t user_input;
343  Serial.println(F("\n\nSelect option - 0: Enable Internal, 1: Disable Internal, 2: Enable External, 3: Disable External"));
344  user_input = read_int();
345  switch (user_input)
346  {
347  case 0:
348  Serial.println(F("Enabling Internal Cal Params"));
350  break;
351  case 1:
352  Serial.println(F("Disabling Internal Cal Params"));
354  break;
355  case 2:
356  Serial.println(F("Enabling External Cal Params"));
358  break;
359  case 3:
360  Serial.println(F("Disabling External Cal Params"));
362  break;
363  }
364 }
365 
366 //! Read stored calibration parameters from nonvolatile EEPROM on demo board
367 //! @return Return 1 if successful, 0 if not
369 // Read the DAC calibration from EEPROM
370 {
371  int16_t intvalid, extvalid;
372  uint8_t i, eeaddr;
373  float dac_count; // The number of codes, 4096 for 12 bits, 65536 for 16 bits
374 
375  Serial.println(F("\n\nReading Calibration parameters from EEPROM..."));
376  float full_scale; // To avoid confusion - in internal ref mode, FS=Vref, in ext mode, FS=2*Vref
377  // Read the cal keys from the EEPROM.
380  // Read the stored reference state
382  // Read external ref V unconditionally, overwrite with defaults if no cal found
384 
385  if (reference_mode == REF_EXTERNAL)
386  {
387  Serial.println(F("Restored external ref. Voltage:"));
388  Serial.println(reference_voltage, 5);
389  }
390  else // EITHER reference is set to internal, OR not programmed in which case default to internal
391  {
392  reference_mode = REF_INTERNAL; // Redundant if already set
393  Serial.println("Internal reference mode set");
394  }
395 
396  // Write the reference mode to the DAC right away
397  LTC2654_write(LTC2654_CS,reference_mode, 0x0F, 0x0000);
398 
399  // Set up default values, shift count, DAC count
400  // Calibration parameters MAY be changed next, if match
401  // between reference mode and stored calibration
402  full_scale = reference_voltage * 2.0; // If external ref mode, this applies.
403  switch (demo_board.option)
404  {
405  case 'A':
406  // LTC2654CUF-L16, 16-bits, 2.5V full scale
407  shift_count = 0;
408  if (reference_mode == REF_INTERNAL) full_scale = 2.5;
409  dac_count = 65536;
410  break;
411  case 'B':
412  // LTC2654CUF-H16, 16-bits, 4.096V full scale
413  shift_count = 0;
414  if (reference_mode == REF_INTERNAL) full_scale = 4.096;
415  dac_count = 65536;
416  break;
417  case 'C':
418  // LTC2654CUF-L12, 12-bits, 2.5V full scale
419  shift_count = 4;
420  if (reference_mode == REF_INTERNAL) full_scale = 2.5;
421  dac_count = 4096;
422  break;
423  case 'D':
424  // LTC2654CUF-H12, 12-bits, 4.096V full scale
425  shift_count = 4;
426  if (reference_mode == REF_INTERNAL) full_scale = 4.096;
427  dac_count = 4096;
428  break;
429  }
430 
431  for (i = 0; i <= 4; i++)
432  {
433  LTC2654_offset[i] = 0;
434  LTC2654_lsb[i] = full_scale / dac_count;
435  }
436 
437  // Restore calibration IF reference mode matches stored calibration
438  eeaddr = 0; // Assume no calibration present or mismatch between cal and reference mode
439 
440  if ((intvalid == EEPROM_CAL_KEY) && (reference_mode == REF_INTERNAL))
441  {
442  eeaddr = INT_CAL_PARAMS_BASE;
443  Serial.println(F("Found internal calibration, restoring...)"));
444  }
445  else if ((extvalid == EEPROM_CAL_KEY) && (reference_mode == REF_EXTERNAL))
446  {
447  eeaddr = EXT_CAL_PARAMS_BASE;
448  Serial.println(F("Found external calibration, restoring...)"));
449  }
450  else Serial.println(F("Calibration not found for this\nreference mode, using ideal calibration"));
451 
452  if (eeaddr != 0) // If cal key was enabled and reference mode is correct, read offset and lsb
453  {
462  LTC2654_offset[4] = LTC2654_offset[0]; // Copy cal value for DAC A to cal value for
463  LTC2654_lsb[4] = LTC2654_lsb[0]; // DAC ALL
464  Serial.println("Calibration Restored");
465  }
466  for (i=0; i<=4; ++i)
467  {
468  Serial.print("DAC ");
469  Serial.print((char) ('A' + i));
470  Serial.print(" offset: ");
471  Serial.print(LTC2654_offset[i]);
472  Serial.print(" , lsb: ");
473  Serial.print(LTC2654_lsb[i]*1000, 4);
474  Serial.println(" mv");
475  }
476  Serial.println("(DAC E applies to ALL DACs selections)");
477  if (eeaddr != 0) return (1);
478  return (0);
479 }
480 
481 //! Store measured calibration parameters to nonvolatile EEPROM on demo board
483 // Store the DAC calibration to the EEPROM
484 {
485  uint8_t eeaddr;
487  {
489  eeaddr = INT_CAL_PARAMS_BASE;
490  }
491  else
492  {
494  eeaddr = EXT_CAL_PARAMS_BASE;
495  }
496 
501  eeprom_write_float(EEPROM_I2C_ADDRESS, LTC2654_lsb[0], eeaddr + 8); // lsb
505  Serial.println(F("Calibration Stored to EEPROM"));
506 }
507 
508 //! Prompt user to enter a voltage or digital code to send to DAC
509 //! @returns user input
511 {
512  int16_t user_input;
513  Serial.print(F("Type 1 to enter voltage, 2 to enter code:"));
514  Serial.flush();
515  user_input = read_int();
516  Serial.println(user_input);
517 
518  if (user_input != 2)
519  return(PROMPT_VOLTAGE);
520  else
521  return(PROMPT_CODE);
522 }
523 
524 //! Get voltage from user input, calculate DAC code based on lsb, offset
525 //! @returns the DAC code
526 uint16_t get_voltage(float LTC2654_lsb, int16_t LTC2654_offset)
527 {
528  float dac_voltage;
529 
530  Serial.print(F("Enter Desired DAC output voltage: "));
531  dac_voltage = read_float();
532  Serial.print(dac_voltage);
533  Serial.println(" V");
534  Serial.flush();
535  return(LTC2654_voltage_to_code(dac_voltage, LTC2654_lsb, LTC2654_offset));
536 }
537 
538 //! Get code to send to DAC directly, in decimal, hex, or binary
539 //! @return code from user
540 uint16_t get_code()
541 {
542  uint16_t returncode;
543  Serial.println("Enter Desired DAC Code");
544  Serial.print("(Format 32768, 0x8000, 0100000, or B1000000000000000): ");
545  returncode = (uint16_t) read_int();
546  Serial.print("0x");
547  Serial.println(returncode, HEX);
548  Serial.flush();
549  return(returncode);
550 }
551 
552 //! Prints the title block when program first starts.
554 {
555  Serial.println("");
556  Serial.println(F("*****************************************************************"));
557  Serial.println(F("* DC1678 Demonstration Program *"));
558  Serial.println(F("* *"));
559  Serial.println(F("* This program demonstrates how to send data to the LTC2654 *"));
560  Serial.println(F("* quad 16/12-bit DAC found on the DC1678 demo board. *"));
561  Serial.println(F("* *"));
562  Serial.println(F("* Set the baud rate to 115200 and select the newline terminator.*"));
563  Serial.println(F("* *"));
564  Serial.println(F("*****************************************************************"));
565 }
566 
567 //! Prints main menu.
568 void print_prompt(int16_t selected_dac)
569 {
570  Serial.println(F("\nCommand Summary:"));
571  Serial.println(F(" 1-Select DAC"));
572  Serial.println(F(" 2-Write to input register (no update)"));
573  Serial.println(F(" 3-Write and update DAC"));
574  Serial.println(F(" 4-Update / power up DAC"));
575  Serial.println(F(" 5-Power down DAC"));
576  Serial.println(F(" 6-Set reference mode"));
577  Serial.println(F(" 7-Calibrate DAC"));
578  Serial.println(F(" 8-Enable / Disable calibration"));
579 
580  Serial.println("\nPresent Values:");
581  Serial.print(" Selected DAC: ");
582  if (selected_dac != 4)
583  Serial.println((char) (selected_dac + 0x41));
584  else
585  Serial.println("All");
586  Serial.print(" DAC Reference: ");
588  Serial.println("Internal");
589  else
590  {
591  Serial.print(F("External "));
592  Serial.print(reference_voltage, 5);
593  Serial.println(F("V reference, please verify"));
594  Serial.print(F("Enter a command:"));
595 
596  }
597  Serial.flush();
598 }
599 
600 //! Calibrate the selected DAC using a voltmeter. The routine
601 //! does a linear curve fit given two data points.
602 void calibrate_dac(uint8_t index)
603 {
604  uint16_t code1 = 0x0200; //! Calibration code 1
605  uint16_t code2 = 0xFFFF; //! Calibration code 2
606  float voltage1; //! Calibration voltage 1
607  float voltage2; //! Calibration voltage 2
608  Serial.println("");
609  Serial.print("Calibrating DAC ");
610  Serial.println((char) (0x41 + index));
611  // Left align 12-bit code1 to 16 bits & write to DAC
613  Serial.print("DAC code set to 0x");
614  Serial.println(code1, HEX);
615  Serial.print("Enter measured DAC voltage:");
616  voltage1 = read_float();
617  Serial.print(voltage1, 6);
618  Serial.println(" V");
619  // Left align 12-bit code2 to 16 bits & write to DAC
621  Serial.print("DAC code set to 0x");
622  Serial.println(code2, HEX);
623  Serial.print("Enter measured DAC voltage:");
624  voltage2 = read_float();
625  Serial.print(voltage2, 6);
626  Serial.println(" V");
627  LTC2654_calibrate(code1, code2, voltage1, voltage2, &LTC2654_lsb[index], &LTC2654_offset[index]);
628 }
struct demo_board_type demo_board
Instantiate demo board structure.
char option
Demo Circuit option (A)
#define EXT_REF_V_BASE
Base address of the stored external reference voltage.
Definition: DC1678A.ino:134
static uint8_t shift_count
The data align shift count.
Definition: DC1678A.ino:157
static int8_t restore_calibration()
Read stored calibration parameters from nonvolatile EEPROM on demo board.
Definition: DC1678A.ino:368
uint8_t eeprom_read_int16(uint8_t i2c_address, int16_t *read_data, uint16_t address)
Read the two byte integer data from the EEPROM starting at address.
const uint8_t address_map[5]
Lookup table for DAC address.
Definition: DC1678A.ino:169
unsigned char user_command
static void loop()
Repeats Linduino loop.
Definition: DC1678A.ino:197
#define EEPROM_I2C_ADDRESS
uint8_t eeprom_write_byte(uint8_t i2c_address, char data, uint16_t address)
Write the data byte to the EEPROM with i2c_address starting at EEPROM address.
#define EXT_CAL_VALID_BASE
Base address of the "external ref calibration valid" flag.
Definition: DC1678A.ino:132
#define INT_CAL_VALID_BASE
Base address of the "internal ref calibration valid" flag.
Definition: DC1678A.ino:130
static uint8_t reference_mode
Tells whether to set internal or external reference.
Definition: DC1678A.ino:158
static void menu_1_select_dac(int16_t *selected_dac)
Select which DAC to operate on.
Definition: DC1678A.ino:251
static float reference_voltage
Reference voltage, either internal or external.
Definition: DC1678A.ino:161
Header File for Linduino Libraries and Demo Code.
static int16_t prompt_voltage_or_code()
Prompt user to enter a voltage or digital code to send to DAC.
Definition: DC1678A.ino:510
#define LTC2654_DAC_A
Definition: LTC2654.h:124
#define LTC2654_CMD_POWER_DOWN
Power down n.
Definition: LTC2654.h:114
uint8_t eeprom_read_float(uint8_t i2c_address, float *read_data, uint16_t address)
Read the four byte float data from the EEPROM starting at address.
static void menu_4_update_power_up_dac(int16_t selected_dac)
Update DAC with data that is stored in input register, power up if sleeping.
Definition: DC1678A.ino:289
#define LTC2654_CMD_WRITE
Write to input register n.
Definition: LTC2654.h:110
#define LTC2654_CMD_WRITE_UPDATE
Write to input register n, update (power up) all.
Definition: LTC2654.h:113
static int16_t LTC2654_offset[5]
DAC offset - index 4 for "all DACs".
Definition: DC1678A.ino:162
static void menu_7_calibrate_dacs()
Calibrate all DACs by measuring two known outputs.
Definition: DC1678A.ino:327
#define LTC2654_CMD_UPDATE
Update (power up) DAC register n.
Definition: LTC2654.h:111
static void menu_3_write_and_update_dac(int16_t selected_dac)
Write data to DAC register (which updates output immediately)
Definition: DC1678A.ino:276
static void print_title()
Prints the title block when program first starts.
Definition: DC1678A.ino:553
#define REF_INTERNAL
Stored reference state is Internal.
Definition: DC1678A.ino:125
static uint16_t get_voltage(float LTC2654_lsb, int16_t LTC2654_offset)
Get voltage from user input, calculate DAC code based on lsb, offset.
Definition: DC1678A.ino:526
uint8_t eeprom_write_float(uint8_t i2c_address, float write_data, uint16_t address)
Write the 4 byte float data to the EEPROM starting at address.
static void store_calibration()
Store measured calibration parameters to nonvolatile EEPROM on demo board.
Definition: DC1678A.ino:482
uint8_t eeprom_write_int16(uint8_t i2c_address, int16_t write_data, uint16_t address)
Write the 2 byte integer data to the EEPROM starting at address.
static void menu_2_write_to_input_register(int16_t selected_dac)
Write data to input register, but do not update DAC output.
Definition: DC1678A.ino:263
#define INT_CAL_PARAMS_BASE
Base address of the internal ref calibration parameters.
Definition: DC1678A.ino:131
static void menu_6_set_reference_mode()
Set reference mode and store to EEPROM.
Definition: DC1678A.ino:303
uint8_t eeprom_read_byte(uint8_t i2c_address, char *data, uint16_t address)
Read a data byte at address from the EEPROM with i2c_address.
QuikEval EEPROM Library.
static void menu_8_enable_calibration()
Enable / Disable calibration.
Definition: DC1678A.ino:340
static void calibrate_dac(uint8_t index)
Calibrate the selected DAC using a voltmeter.
Definition: DC1678A.ino:602
void quikeval_SPI_init(void)
Configure the SPI port for 4Mhz SCK.
Definition: LT_SPI.cpp:151
void LTC2654_calibrate(uint16_t dac_code1, uint16_t dac_code2, float voltage1, float voltage2, float *LTC2654_lsb, int16_t *LTC2654_offset)
Calculate the LTC2654 offset and LSB voltage given two measured voltages and their corresponding code...
Definition: LTC2654.cpp:115
int8_t discover_demo_board(char *demo_name)
Read the ID string from the EEPROM and determine if the correct board is connected.
LT_SPI: Routines to communicate with ATmega328P&#39;s hardware SPI port.
#define LTC2654_DAC_C
Definition: LTC2654.h:126
LT_I2C: Routines to communicate with ATmega328P&#39;s hardware I2C port.
#define LTC2654_DAC_B
Definition: LTC2654.h:125
static void menu_5_power_down_dac(int16_t selected_dac)
Power down DAC.
Definition: DC1678A.ino:296
char demo_name[]
Demo Board Name stored in QuikEval EEPROM.
Definition: DC1880A.ino:97
void quikeval_SPI_connect()
Connect SPI pins to QuikEval connector through the Linduino MUX. This will disconnect I2C...
Definition: LT_SPI.cpp:138
int32_t read_int()
#define STORED_REF_STATE_BASE
Base address of the stored reference state.
Definition: DC1678A.ino:129
static int index
float read_float()
static void setup()
Initialize Linduino.
Definition: DC1678A.ino:179
#define EXT_CAL_PARAMS_BASE
Base address of the external ref calibration parameters.
Definition: DC1678A.ino:133
#define LTC2654_DAC_D
Definition: LTC2654.h:127
#define LTC2654_CS
Define the SPI CS pin.
Definition: LTC2654.h:104
void quikeval_I2C_init(void)
Initializes Linduino I2C port.
Definition: LT_I2C.cpp:394
#define REF_EXTERNAL
Stored reference state is External.
Definition: DC1678A.ino:126
static uint8_t demo_board_connected
Set to 1 if the board is connected.
Definition: DC1678A.ino:156
static int i
Definition: DC2430A.ino:184
static uint16_t get_code()
Get code to send to DAC directly, in decimal, hex, or binary.
Definition: DC1678A.ino:540
static void print_prompt(int16_t selected_dac)
Prints main menu.
Definition: DC1678A.ino:568
#define LTC2654_DAC_ALL
Definition: LTC2654.h:128
static float LTC2654_lsb[5]
The LTC2654 lsb - index 4 for "all DACs".
Definition: DC1678A.ino:163
#define EEPROM_CAL_KEY
uint16_t LTC2654_voltage_to_code(float dac_voltage, float LTC2654_lsb, int16_t LTC2654_offset)
Calculate a LTC2654 DAC code given the desired output voltage and DAC address (0-3) ...
Definition: LTC2654.cpp:94
void LTC2654_write(uint8_t cs, uint8_t dac_command, uint8_t dac_address, uint16_t dac_code)
Write the 16-bit dac_code to the LTC2654.
Definition: LTC2654.cpp:79
LTC2654: Quad SPI 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference.