Texas Instruments LDC1000 User manual

LDC1000/LDC1041/LDC1051 Evaluation Module
User's Guide
Literature Number: SNAU150A
September 2013–Revised March 2014

Chapter 1
SNAU150A–September 2013–Revised March 2014
LDC1000/LDC1041/LDC1051 Evaluation Module
1.1 Overview
The LDC10xx Evaluation Module is designed to provide an example LC tank and coil structure application
which interfaces to a host computer. The module can be used independently of the GUI by the on-board
embedded LED, which demonstrates threshold detection.
Figure 1-1. Evaluation Module
The EVM includes an example PCB sensor which is a 2 layer, 23 turn, 14mm diameter inductor with a
100pF 1% NP0 capacitor connected in parallel to form an LC tank.
The EVM is perforated at two locations to provide the option to interface to various system configurations.
The first perforation, between the coil and the LDC10xx, can be used to snap off the PCB coil and connect
a custom coil. The second perforation is between the LDC10xx and the MSP430, and provides the option
to connect the LDC10xx and the sensor to a different system or to use multiple sensors in one system for
prototyping.
Figure 1-2. LDC1000+Sensor
When the evaluation module first powers up from the USB port, it will flash a series of green and red LED
lights to indicate self-test. When the self-test is finished, the green LED indicates the status of the
LDC10xx INTB pin. When the INTB pin is asserted, the green LED is lit. By default, INTB is configured
for threshold detection.
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Chapter 2
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Quick Start Guide LDC10xx Evaluation Module
2.1 LDC10xx Evaluation Module Overview
The LDC10xx Evaluation Module (EVM) enables the user to test out analog and digital capabilities of the
LDC10xx Inductance-to-Digital Converter. The EVM is a USB device used with a host computer and
accessed using the Inductive Sensing Graphical User Interface (GUI) software, which is documented in
Chapter 3.
To quickly get started on the LDC10xx GUI, follow the steps below to load and configure a device:
2.1.1 Evaluation Module
Set Up Requirements:
1. The LDC10xx GUI and drivers must be installed on the host.
2. Available USB port on host computer.
Loading and Running:
1. Plug the EVM into the host computer. The host computer should automatically detect the device as a
LDC10xxEVM.
2. Launch the GUI. It should automatically detect the presence of the EVM, read all the configuration
registers, and begin streaming data.
Figure 2-1. Streaming Section
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Reconnecting the EVM
If the EVM is disconnected from the host at any time, simply reconnect the device and the GUI will
automatically discover and re-establish the streaming abilities with the device.
Configuring the Device Manually
1. The GUI puts the device in streaming mode by default. Click on "Stop" in the streaming section to stop
continuous LDC10xx conversion.
Figure 2-2. Stop Streaming
2. Click on the Configuration icon in the main window toolbar.
Figure 2-3. Configuration Icon
3. Select the parameter to change. When entering the comparator thresholds, press ENTER to confirm
the change. Changes are applied immediately.
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Figure 2-4. Configuration Section
Saving Device Configuration
1. Click on the "Save" icon in the toolbar.
Figure 2-5. Save Icon
2. Type a name for the file.
Configuring the Device with Configuration File Defaults
1. The GUI puts the device in streaming mode by default. Click on "Stop" in the streaming section to stop
streaming.
2. Click on the "Open" icon in the toolbar.
Figure 2-6. Open Icon
3. Select the configuration file.
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4. After the configuration file is loaded, current values are written once to all supported registers. To
restore defaults defined in the configuration file, click on Restore Defaults to write all current registers
with the new configuration file defaults.
Figure 2-7. Restore Defaults
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Chapter 3
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Inductive Sensing GUI User Guide
3.1 Inductive Sensing GUI Overview
The inductive sensing GUI provides graphical configuration and streaming support for the LDC10xx. The
GUI package includes drivers for use with the LDC10xx Evaluation Modules (EVM). The EVM
provides a device abstraction layer for the GUI to communicate with the LDC10xx through SPI, and
includes other extended functionality.
3.2 Host Platform Requirements
The Inductive Sensing GUI supports:
• 32-bit and 64-bit Windows 7
• 32-bit and 64-bit Windows XP
The host machine is required for device configuration and data streaming. Below are the steps which are
necessary to prepare the EVM for the GUI:
• The GUI must be installed on the host.
• The EVM driver must be installed on the host.
• The EVM must be connected to a full speed USB port (USB 1.0 or above).
3.3 EVM Information
For the TI LDC10xx EVM:
• The EVM allows the GUI to:
– Configuring register data through SPI (CSB, SCLK, SDO, SDI)
– Stream register data through SPI
– Stream register data through SPI
– Detect interrupts through SPI
3.4 Icon Toolbar
The icon toolbar contains various icons which navigate between sections and perform various functions.
Figure 3-1. Icon Toolbar
Name Description Icon
Connection Information Indicates whether an EVM is connected to • EVM is connected
the PC, and if so, provides details of the
connected EVM
• EVM is disconnected
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Open Opens saved register settings and
defaults
Save Saves all current register settings and
defaults
Register Settings Show LDC10xx Register Settings
Configuration Show EVM Configuration
Streaming Show Streaming Section
3.5 Multiple EVMs
To connect multiple EVMs to a single host, multiple instances of the GUI should be launched. Each EVM
will interface to only one instance of the GUI; multiple instances cannot connect to the same EVM. Use
the following procedure to setup multiple EVMs:
1. Connect the desired number of EVMs to the available USB ports.
2. Open one instance of the GUI, note the COM port number at the top of the GUI. This EVM is the
highest priority. Remove and replace each EVM individually until the COM port number changes. Note
the new COM port number.
3. This EVM is the next highest priority. Repeat this process until no EVMs are connected and the EVM
with the lowest priority has been identified.
4. When all of the EVMs are to be used simultaneously, open one GUI for each EVM and plug in the
EVMs from lowest priority to highest priority – each will claim their own instance of GUI.
3.6 General Configuration
In the configuration section, all registers of the device can be accessed. To access this section, streaming
must be stopped.
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Figure 3-2. Configuration Section
In the configuration window, select the parameter to change. When entering the comparator thresholds,
press ENTER to confirm the change. Changes are applied immediately.
Press “Read All” to refresh all configuration, status, and data settings.
Press “Restore from Defaults” to write values from the default column (if they exist) to the current register
values.
Press "Save Values as Defaults" to set the current configuration settings as the default settings.
3.7 Register Settings
In the register settings section, all registers of the device can be accessed. To read/write registers,
streaming must be stopped.
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Figure 3-3. Register Settings
Double-click on a register in the table to read/write. If a register is read only, the selected register is read
immediately and the table value updated. If the register is read/write, a dialog pops up and the user can
set a new register value. If the value is not changed, it will default to a read.
Figure 3-4. Read/Write Register Dialog
Press “Read All” to refresh all configuration, status, and data.
Press “Restore Defaults” to write values from the default column (if they exist) to the current register value.
3.8 Data Streaming
Data is streamed from the EVM to the GUI when streaming is started. The sampling rate of the EVM and
the number of samples to plot can be configured. The sampling rate is the rate at which the micro-
controller on the EVM retrieves a measurement from the LDC10xx.
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Figure 3-5. Streaming Configuration
The sampling rate can only be set when streaming is stopped.
3.8.1 Average, Point, Min, Max Values
Average is the default display type. To toggle between sample point, min, and max values, right-click on
the GUI. The various display modes are:
Average Mode The average of all the data points currently in the plot
Point Mode The newest data point value currently in the plot
Min Mode The minimum data point value currently in the plot
Max Mode The maximum data point value currently in the plot
A larger number of samples would result in a larger averaging window.
3.8.2 Zooming and Scaling
Plots are interactive. Zooming options are available by right-clicking the plot and selecting an option from
the context menu.
Figure 3-6. Plot Context Menu
Zoom to... Zooms to window
Autoscale Autoscales the data in the plot
Reset Resets the Zoom window to its default setting
Help Displays shortcut keys and mouse mappings for scaling and
zooming
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3.8.3 Threshold Display
To display RPThresholds, right-click the plot and select “Toggle Markers.”
Figure 3-7. Toggling Markers
3.8.4 Inductance Raw Data
To display the raw frequency count output data instead of the inductance data, right click on the
Inductance plot and select "Toggle Data Type".
Figure 3-8. Switching Display Units Between Inductance and Frequency Count
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3.8.5 LDCLK
The LDC10xx uses a reference clock generated by the MCU on the EVM to measure the inductance. The
clock frequency can be changed to several settings by the LDCLK selection. The higher the frequency of
the LDCLK, the more accurately the LDC10xxEVM can measure the inductance. When the LDCLK is set
to OFF, then no inductance measurements are performed and the inductance measurement graph is not
displayed. Note that it may take a some time for the inductance measurement result to stabilize after
changing the LDCLK frequency.
Figure 3-9. LDCLK Configuration
3.8.6 LED
The Red and Green LEDs on the LDC10xxEVM can be turned on or off using this menu.
3.9 Saving and Loading
3.9.1 Configurations
Configurations can be saved and loaded. To save a configuration, click on the "Save" icon. To load a
configuration, click on the "Open" icon.
Configurations include all register names, current values, and default values. They are saved in Comma-
Separated Files (*.csv) and can be modified using a text or spreadsheet editor.
3.9.2 Plot Data
Right-click a plot and select “Save Data…”
Data can be saved to a new file or an existing one. If an existing file is chosen, data will be appended.
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Figure 3-10. Saving Data from a Plot
3.9.3 Data Logging
Measured data from the LDC10xxEVM can be saved to a text file by using the Logging features, which
are located on the bottom of the main GUI window.
Figure 3-11. Data Logging
The data is saved in an ASCII text file which contains the time of data capture, the RPmeasurement, the
inductance measurement, and the raw inductance data. Data can be logged either as a single
measurement or as a continuous stream of data. To save a single measurement, set the middle button to
"Single"; if a continuous log is desired, change the setting to "Continuous". Once the mode is set, press
the "Log Data" button to save the file. A file save dialogue will open asking for the file name. It is
recommended to add ".txt" to the end of the filename if a text editor is to be used to analyze the data, or
use an extension of ".csv" if a spreadsheet program is to be used. When the Logging save mode is
continuous, the GUI will continuously save the data from the LDC10xxEVM; to stop the data saving, press
the "Log Data" button a second time.
3.10 Using a Custom Sensor
The coil plus capacitor portion of the LDC10xx Evaluation Module is perforated so that it can be snapped
off and replaced with a custom LC tank.
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Figure 3-12. Custom Sensor Connection
By default, the Evaluation Module is fitted with a 100pF 1% NP0 sensor capacitor in parallel to the PCB
coil. When the sensor capacitor value is changed as a result of replacing the default LC tank with a
custom inductive sensor, it is necessary to input the new capacitor value into the Sensor Capacitor field in
the GUI to ensure that the inductance data is calculated correctly.
Figure 3-13. Sensor Capacitor Setting
3.11 Additional Resources
Several resources are included in the GUI installation directory (typically C:\Program Files (x86)\Texas
Instruments LDC1000 EVM). These resources can be useful for development of LDC10xx projects.
3.11.1 PCB Information
In the installation directory, refer to the PCB subdirectory. In the PCB/Fabrication Drawing subdirectory the
schematic, Bill of Materials, and a printout of the layout is included. The Gerbers and manufacturing files
are included the PCB/Gerber subdirectory.
3.11.2 Firmware Resources
In the installation directory, refer to Firmware subdirectory. The firmware image is provided, along with the
source code and Code Composer project workspace for the LDC10xx EVM firmware.
3.11.3 Matlab Interface
A Matlab interface library is included in the installation. Refer to installation directory and then navigate to
Matlab\Doc\html\index.html for documentation on the provided functions.
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3.11.4 Labview Resources
A Labview interface library is included in the installation. The Labview subdirectory contains VIs to read
and write LDC10xx registers and to stream data from the LDC10xxEVM.
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Chapter 4
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Schematics
4.1 LDC10xx EVM Schematics
Figure 4-1. EVM Layout
Figure 4-2. Top Layer
Figure 4-3. Bottom Layer
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Chapter 5
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Bill of Materials
Designator Quantity Description Manufacturer Part Number
C1 1 CAP, CERM, 2.2uF, 10V, Kemet C0603C225K8PACTU
+/-10%, X5R, 0603
C2 1 CAP CER 10UF 10V 10% TDK Corporation C1608X5R1A106K080AC
X5R 0603
C3, C5, C11, C12, C16, 6 CAP CER 0.1UF 16V 5% Murata Electronics North GRM155R71C104JA88D
C19 X7R 0402 America
C4 1 CAP, CERM, 0.01uF, TDK C1608C0G1E103J
25V, +/-5%, C0G/NP0,
0603
C6 1 CAP CER 220PF 50V 1% TDK Corporation C1005C0G1H221F050BA
NP0 0402
C7 1 CAP, CERM, 2200pF, Kemet C0603X222K5RACTU
50V, +/-10%, X7R, 0603
C8, C9 2 CAP CER 18PF 100V 5% MuRata GRM1885C2A180JA01D
NP0 0603
C10 1 CAP, CERM, 220pF, 50V, AVX 06035A221FAT2A
+/-1%, C0G/NP0, 0603
C13, C15 2 CAP, CERM, 1uF, 10V, MuRata GRM155R61A105KE15D
+/-10%, X5R, 0402
C14 1 CAP CER 0.056UF 16V Kemet C0402C563J4RACTU
5% X7R 0402
C17 1 CAP, CERM, 0.47uF, Kemet C0603C474K8RACTU
10V, +/-10%, X7R, 0603
C18 1 CAP CER 20PF 50V 5% Kemet C0805C200J5GACTU
NP0 0805
C_Tank 1 CAP CER 100PF 50V 1% AVX Corporation 06035A101FAT2A
NP0 0603
D1 1 LED SMARTLED GREEN OSRAM Opto LG L29K-G2J1-24-Z
570NM 0603 Semiconductors Inc
D2 1 LED 660NM SUPER RED Lumex Opto/Components SML-LX0603SRW-TR
DIFF 0603SMD Inc
D21 1 Diode, Zener, 5.6V, Diodes Inc. MMSZ5232B-7-F
500mW, SOD-123
FID1, FID2, FID3 3 Fiducial mark. There is N/A N/A
nothing to buy or mount.
J1 1 Connector, USB Type A, Molex 48037-2200
4POS R/A, SMD
L1 1 INDUCTOR POWER TDK Corporation VLS201610ET-100M
10UH .45A SMD
R1, R2 2 RES, 33 ohm, 5%, Vishay-Dale CRCW040233R0JNED
0.063W, 0402
R5 1 RES, 33k ohm, 5%, Vishay-Dale CRCW040233K0JNED
0.063W, 0402
R6, R7 2 RES 1K OHM 1/10W 5% Panasonic Electronic ERJ-2GEJ102X
0402 SMD Components
R20 1 RES,1M ohm, 5%, Yageo RC0402JR-071ML
0.063W, 0402
R40 1 RES 1.5K OHM 1/16W Vishay Dale CRCW04021K50JNED
5% 0402 SMD
18 Bill of Materials SNAU150A–September 2013–Revised March 2014
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Designator Quantity Description Manufacturer Part Number
U1 1 Micropower 150 mA Low- Texas Instruments LP2985AIM5-3.3/NOPB
Noise Ultra Low-Dropout
Regulator, 5-pin SOT-23,
Pb-Free
U2 1 4-CHANNEL ESD- Texas Instruments TPD4E004DRY
PROTECTION ARRAY
FOR HIGH-SPEED DATA
INTERFACES, DRY006A
U3 1 MCU Texas Instruments MSP430F5528IRGCR
U4 1 Inductance to Digital Texas instruments LDC1000
Converter
Y1 1 CRYSTAL 24.000MHZ Abracon Corporation ABMM-24.000MHZ-B2-T
18PF SMD
J2 0 TERM BLOCK 2POS FCI 20020327-D021B01LF
3.81MM PCB HORIZ
J4 0 Header, TH, 100mil, 2x1, Samtec, Inc. TSW-102-07-G-S
Gold plated, 230 mil
above insulator
19
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Revision History www.ti.com
Revision History
Changes from Original (September 2013) to A Revision ............................................................................................... Page
• Added new part numbers LDC1041/LDC1051 ........................................................................................ 2
• Additional sections on design resources installed with GUI, how to use a custom sensor, and information on new data
logging feature............................................................................................................................. 3
• Added New Section ..................................................................................................................... 14
• Changed Changed Schematic to Vector graphic for better display. .............................................................. 17
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
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