Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board

Linear Technology DC742A Demonstration Board. More...

Detailed Description

Linear Technology DC742A Demonstration Board.

LTC2449: 24-Bit, 16-Channel Delta Sigma ADC with Selectable Speed/Resolution.

Linear Technology DC979A Demonstration Board. LTC2442: 24-Bit, 4-Channel Delta Sigma ADC with Integrated Amplifier

Linear Technology DC845A Demonstration Board. LTC2448: 24-Bit, 8-/16-Channel Delta Sigma ADCs with Selectable Speed/Resolution

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. Additionally,
   an external power supply is required to provide a negative voltage for Amp V-.
   Set it to anywhere from -1V to -5V. Set Amp V+ to Vcc. Ensure the COM and REF-
   pins are connected to ground. The REF+ pin should be connected to +5V.

  How to test Single-Ended mode:
   The voltage source should be connected to the ADC such that the negative lead is
   connected to the COM(common) pin. The positive lead may be connected to any
   channel input. Ensure voltage is within analog input voltage range -0.3 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 -0.3V to +2.5V. Swapping input voltages results in a
   reversed polarity reading.

  How to calibrate:
   Apply 100mV CH0 with respect to COM. Next, measure this voltage with a precise
   voltmeter and enter this value. (This takes the reading.) Now apply approximately
   2.40 volts to CH0. Measure this voltage with a precise voltmeter and enter this
   value. Calibration is now stored in EEPROM. Upon start-up the calibration values
   will be restored.

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

http://www.linear.com/product/LTC2449 http://www.linear.com/product/LTC2442 http://www.linear.com/product/LTC2448

http://www.linear.com/product/LTC2449#demoboards http://www.linear.com/product/LTC2442#demoboards http://www.linear.com/product/LTC2448#demoboards

Copyright 2018(c) Analog Devices, Inc.

All rights reserved.

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Definition in file DC742A.ino.

Go to the source code of this file.

Functions

static void print_title ()
 Prints the title block when program first starts. More...
 
static void print_prompt ()
 Prints main menu. More...
 
static void print_user_command (uint8_t menu)
 Display selected differential channels. More...
 
static void store_calibration ()
 Store measured calibration parameters to nonvolatile EEPROM on demo board. More...
 
static int8_t restore_calibration ()
 Read stored calibration parameters from nonvolatile EEPROM on demo board. More...
 
static int8_t menu_1_read_single_ended ()
 Read channels in single-ended mode. More...
 
static int8_t menu_2_read_differential ()
 Read channels in differential mode. More...
 
static int8_t menu_3_calibrate ()
 Calibrate ADC given two known inputs. More...
 
static void menu_4_set_OSR ()
 Set Oversample Ratio (OSR) More...
 
static void menu_5_set_1X2X ()
 Set 1X or 2X mode. More...
 
static void menu_6_en_dis_cal ()
 Enable / Disable calibration without actually touching stored calibration values. More...
 
static void setup ()
 Initialize Linduino. More...
 
static void loop ()
 Repeats Linduino loop. More...
 

Variables

static uint8_t demo_board_connected
 Set to 1 if the board is connected. More...
 
static int16_t OSR_mode = LTC2449_OSR_32768
 The LTC2449 OSR setting. More...
 
static int16_t two_x_mode = LTC2449_SPEED_1X
 The LTC2449 2X Mode settings. More...
 
static float LTC2449_lsb = 9.3132258E-9
 Ideal LSB voltage for a perfect part. More...
 
static int32_t LTC2449_offset_code = 0
 Ideal offset for a perfect part. More...
 
const uint16_t BUILD_COMMAND_SINGLE_ENDED [16]
 Lookup table to build the command for single-ended mode. More...
 
const uint16_t BUILD_COMMAND_DIFF [16]
 Lookup table to build the command for differential mode. More...
 
const uint16_t BUILD_OSR_COMMAND [10]
 Lookup table to build the command for OSR. More...
 
const uint16_t BUILD_1X_2X_COMMAND [2] = {LTC2449_SPEED_1X, LTC2449_SPEED_2X}
 Lookup table to build 1X / 2X bits. More...
 
const uint16_t MISO_TIMEOUT = 1000
 MISO timeout constant. More...
 

Function Documentation

◆ loop()

static void loop ( void  )
static

Repeats Linduino loop.

Definition at line 175 of file DC742A.ino.

◆ menu_1_read_single_ended()

static int8_t menu_1_read_single_ended ( )
static

Read channels in single-ended mode.

Returns
0 if successful, 1 is failure

Definition at line 307 of file DC742A.ino.

◆ menu_2_read_differential()

static int8_t menu_2_read_differential ( )
static

Read channels in differential mode.

Returns
0 if successful, 1 is failure

Definition at line 396 of file DC742A.ino.

◆ menu_3_calibrate()

static int8_t menu_3_calibrate ( )
static

Calibrate ADC given two known inputs.

Returns
0 if successful, 1 is failure

Definition at line 494 of file DC742A.ino.

◆ menu_4_set_OSR()

static void menu_4_set_OSR ( )
static

Set Oversample Ratio (OSR)

Returns
void

Definition at line 550 of file DC742A.ino.

◆ menu_5_set_1X2X()

static void menu_5_set_1X2X ( )
static

Set 1X or 2X mode.

Returns
void

Definition at line 579 of file DC742A.ino.

◆ menu_6_en_dis_cal()

static void menu_6_en_dis_cal ( )
static

Enable / Disable calibration without actually touching stored calibration values.

Returns
void

Definition at line 616 of file DC742A.ino.

◆ print_prompt()

static void print_prompt ( )
static

Prints main menu.

Definition at line 236 of file DC742A.ino.

◆ print_title()

static void print_title ( void  )
static

Prints the title block when program first starts.

Definition at line 221 of file DC742A.ino.

◆ print_user_command()

static void print_user_command ( uint8_t  menu)
static

Display selected differential channels.

Displaying single-ended channels is straightforward; not so with differential because the inputs can take either polarity.

Definition at line 249 of file DC742A.ino.

◆ restore_calibration()

static int8_t restore_calibration ( )
static

Read stored calibration parameters from nonvolatile EEPROM on demo board.

Returns
return 1 if successful, 0 if not

Definition at line 641 of file DC742A.ino.

◆ setup()

static void setup ( void  )
static

Initialize Linduino.

Definition at line 157 of file DC742A.ino.

◆ store_calibration()

static void store_calibration ( )
static

Store measured calibration parameters to nonvolatile EEPROM on demo board.

Returns
void

Definition at line 605 of file DC742A.ino.

Variable Documentation

◆ BUILD_1X_2X_COMMAND

const uint16_t BUILD_1X_2X_COMMAND[2] = {LTC2449_SPEED_1X, LTC2449_SPEED_2X}

Lookup table to build 1X / 2X bits.

Build the command for 1x or 2x mode

Definition at line 151 of file DC742A.ino.

◆ BUILD_COMMAND_DIFF

const uint16_t BUILD_COMMAND_DIFF[16]
Initial value:
}
#define LTC2449_P10_N11
Definition: LTC2449.h:191
#define LTC2449_P3_N2
Definition: LTC2449.h:180
#define LTC2449_P14_N15
Definition: LTC2449.h:197
#define LTC2449_P11_N10
Definition: LTC2449.h:192
#define LTC2449_P6_N7
Definition: LTC2449.h:185
#define LTC2449_P0_N1
Definition: LTC2449.h:176
#define LTC2449_P12_N13
Definition: LTC2449.h:194
#define LTC2449_P5_N4
Definition: LTC2449.h:183
#define LTC2449_P4_N5
Definition: LTC2449.h:182
#define LTC2449_P13_N12
Definition: LTC2449.h:195
#define LTC2449_P2_N3
Definition: LTC2449.h:179
#define LTC2449_P9_N8
Definition: LTC2449.h:189
#define LTC2449_P8_N9
Definition: LTC2449.h:188
#define LTC2449_P1_N0
Definition: LTC2449.h:177
#define LTC2449_P7_N6
Definition: LTC2449.h:186
#define LTC2449_P15_N14
Definition: LTC2449.h:198

Lookup table to build the command for differential mode.

Build the command for differential mode

Definition at line 139 of file DC742A.ino.

◆ BUILD_COMMAND_SINGLE_ENDED

const uint16_t BUILD_COMMAND_SINGLE_ENDED[16]
Initial value:
}
#define LTC2449_CH0
Definition: LTC2449.h:156
#define LTC2449_CH12
Definition: LTC2449.h:168
#define LTC2449_CH14
Definition: LTC2449.h:170
#define LTC2449_CH3
Definition: LTC2449.h:159
#define LTC2449_CH5
Definition: LTC2449.h:161
#define LTC2449_CH1
Definition: LTC2449.h:157
#define LTC2449_CH11
Definition: LTC2449.h:167
#define LTC2449_CH13
Definition: LTC2449.h:169
#define LTC2449_CH8
Definition: LTC2449.h:164
#define LTC2449_CH6
Definition: LTC2449.h:162
#define LTC2449_CH9
Definition: LTC2449.h:165
#define LTC2449_CH10
Definition: LTC2449.h:166
#define LTC2449_CH15
Definition: LTC2449.h:171
#define LTC2449_CH2
Definition: LTC2449.h:158
#define LTC2449_CH7
Definition: LTC2449.h:163
#define LTC2449_CH4
Definition: LTC2449.h:160

Lookup table to build the command for single-ended mode.

Builds the command for single-ended mode

Definition at line 132 of file DC742A.ino.

◆ BUILD_OSR_COMMAND

const uint16_t BUILD_OSR_COMMAND[10]
Initial value:
}
#define LTC2449_OSR_2048
Definition: LTC2449.h:217
#define LTC2449_OSR_32768
Definition: LTC2449.h:221
#define LTC2449_OSR_8192
Definition: LTC2449.h:219
#define LTC2449_OSR_16384
Definition: LTC2449.h:220
#define LTC2449_OSR_512
Definition: LTC2449.h:215
#define LTC2449_OSR_64
Definition: LTC2449.h:212
#define LTC2449_OSR_128
Definition: LTC2449.h:213
#define LTC2449_OSR_1024
Definition: LTC2449.h:216
#define LTC2449_OSR_256
Definition: LTC2449.h:214
#define LTC2449_OSR_4096
Definition: LTC2449.h:218

Lookup table to build the command for OSR.

Build the command for OSR

Definition at line 146 of file DC742A.ino.

◆ demo_board_connected

uint8_t demo_board_connected
static

Set to 1 if the board is connected.

Definition at line 123 of file DC742A.ino.

◆ LTC2449_lsb

float LTC2449_lsb = 9.3132258E-9
static

Ideal LSB voltage for a perfect part.

Definition at line 126 of file DC742A.ino.

◆ LTC2449_offset_code

int32_t LTC2449_offset_code = 0
static

Ideal offset for a perfect part.

Definition at line 127 of file DC742A.ino.

◆ MISO_TIMEOUT

const uint16_t MISO_TIMEOUT = 1000

MISO timeout constant.

Definition at line 154 of file DC742A.ino.

◆ OSR_mode

int16_t OSR_mode = LTC2449_OSR_32768
static

The LTC2449 OSR setting.

Definition at line 124 of file DC742A.ino.

◆ two_x_mode

int16_t two_x_mode = LTC2449_SPEED_1X
static

The LTC2449 2X Mode settings.

Definition at line 125 of file DC742A.ino.