Texas Instruments LDC2114 User manual

LDC2114 Evaluation Module for Inductive
Touch Applications
User's Guide
Literature Number: SNOU144
December 2016

2SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
Table of Contents
Contents
1 Overview............................................................................................................................. 6
2 Compatible Sensor EVM ....................................................................................................... 7
3 Main EVM elements.............................................................................................................. 7
4 Sensing Solutions EVM GUI .................................................................................................. 8
4.1 System Requirements................................................................................................... 8
4.2 Installation Instructions .................................................................................................. 9
4.3 Starting the GUI......................................................................................................... 16
4.4 Navigating the GUI ..................................................................................................... 17
4.5 Connecting the EVM ................................................................................................... 19
4.6 Configuring the EVM Using the Register Page..................................................................... 19
4.6.1 Automatically Update GUI Register Values Using Auto Read ........................................ 19
4.6.2 Manually Update Device Register Values ............................................................... 20
4.6.3 Reading Register Values Without Auto Read........................................................... 22
4.6.4 Saving Device Configurations............................................................................. 24
4.6.5 Loading Previously Saved Configurations............................................................... 24
4.7 Configuring the EVM Using the Configuration Page............................................................... 25
4.7.1 Changing registers through the Configuration Pane ................................................... 25
4.7.2 Selecting the Mode of Operation and Scan Rate....................................................... 26
4.7.3 Interrupt polarity............................................................................................. 26
4.7.4 Base-tracking Increment ................................................................................... 26
4.7.5 LC Resonant Frequency Divider (Pre-scaler)........................................................... 26
4.7.6 Channel Settings............................................................................................ 27
4.7.7 Algorithm Settings........................................................................................... 27
4.7.8 Calculator .................................................................................................... 27
4.7.9 Status......................................................................................................... 28
4.8 Streaming Measurement Data........................................................................................ 28
4.8.1 Choosing Visible Channels ................................................................................ 28
4.8.2 Logging Data to a File...................................................................................... 29
4.8.3 Starting and Stopping Data Streaming................................................................... 30
4.8.4 Data Statistics ............................................................................................... 31
4.8.5 Configuring the Graph...................................................................................... 32
4.8.6 Navigating the Data Streaming Buffer.................................................................... 34
4.9 Updating the EVM Firmware .......................................................................................... 36
5 LDC2114 EVM REV A Schematics and Layout........................................................................ 41
6 LDC2114EVM REV A Bill of Materials.................................................................................... 52

www.ti.com
3
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
List of Figures
List of Figures
1 LDC2114 Evaluation Module............................................................................................... 6
2 Main EVM elements......................................................................................................... 7
3 User Account Control Prompt.............................................................................................. 9
4 Software Installer Wizard.................................................................................................. 10
5 Software Installer License Agreement................................................................................... 10
6 Software Installation Directory............................................................................................ 11
7 Software Installer Ready .................................................................................................. 12
8 Software Installer in Progress ............................................................................................ 12
9 Device Driver Installer Wizard............................................................................................ 13
10 Device Driver Installer in Progress....................................................................................... 14
11 Device Driver Installer Completed ....................................................................................... 15
12 Software Installer Completed............................................................................................. 15
13 Splash Screen .............................................................................................................. 16
14 Introduction Page........................................................................................................... 17
15 Mouse Hovered Over Menu Button...................................................................................... 18
16 Menu Display After Clicking Button...................................................................................... 18
17 EVM Connected to GUI ................................................................................................... 19
18 Selecting Auto Read Interval on Register Page ....................................................................... 20
19 Selecting a Register's Current Value for Editing on Register Page ................................................. 21
20 Hovering Mouse Over Register Bit Value on Register Page ........................................................ 22
21 Selecting a Register on Register Page.................................................................................. 23
22 Reading the Current Device Register Value on Register Page ..................................................... 23
23 Save Register Values to File on Register Page........................................................................ 24
24 Loading Previously Saved Register Values from File on Register Page ........................................... 25
25 Global Button Settings, Channel Settings on Configuration Page................................................... 26
26 Algorithm Settings and Calculator on Configuration Page............................................................ 27
27 Device Status............................................................................................................... 28
28 Select the Data Graph on Data Streaming Page ...................................................................... 29
29 Select Log File Button on Data Streaming Page....................................................................... 30
30 Start Button on Data Streaming Page................................................................................... 31
31 Show Statistics Button on Data Streaming Page ...................................................................... 32
32 Hide Statistics Button on Data Streaming Page ....................................................................... 32
33 Show Graph Configuration Button on Data Streaming Page......................................................... 33
34 Graph Configuration Button on Data Streaming Page ................................................................ 34
35 Changing Number of Samples Displayed in Data Graph ............................................................ 35
36 Displaying Previous Data Samples on the Data Streaming Page ................................................... 36
37 Select TI-TXT File Button on Firmware Upload Page ................................................................ 37
38 Selecting TI-TXT Firmware File for Upload to EVM .................................................................. 38
39 Upload Firmware Button on Firmware Upload Page ................................................................. 39
40 Firmware Upload in Progress ............................................................................................ 39
41 Firmware Upload Success ............................................................................................... 40
42 Bridge between LDC and MSP430 ...................................................................................... 41
43 PU/PD for LDC inputs ..................................................................................................... 41
44 Power: 1.8V LDO for LDC211x........................................................................................... 42
45 Button press LEDs ......................................................................................................... 42
46 LDC2114 .................................................................................................................... 43
47 Level shift from 1.8V LDC211x to 3.3V MSP430 ...................................................................... 44

www.ti.com
4SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
List of Figures
48 Level shift for I2C........................................................................................................... 45
49 USB connector.............................................................................................................. 46
50 Power: 3.3V LDC for MSP430............................................................................................ 46
51 MSP430 ..................................................................................................................... 47
52 MSP430 GPIO Breakout connector and General purpose LEDs.................................................... 48
53 LDC2114 Layout Top Layer - Overview................................................................................. 49
54 LDC2114 Layout Top Layer – Signals and Components............................................................. 49
55 LDC2114 Layout MidLayer 1 – Ground Plane ......................................................................... 50
56 LDC2114 Layout MidLayer 2 – Signals and Power Plane............................................................ 50
57 LDC2114 Layout Bottom Layer – Signals Plane....................................................................... 51
58 LDC2114 Bottom Layer - Overview...................................................................................... 51

www.ti.com
5
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
List of Tables
List of Tables
1 List of Evaluation modules.................................................................................................. 6
2 Connection options ......................................................................................................... 7
3 BOM for LDC2114EVM rev A ............................................................................................ 52

6SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital Converter
User's Guide
SNOU144–December 2016
LDC2114 Evaluation Module for Inductive Touch
Inductance to Digital Converter
1 Overview
The LDC2114 EVM demonstrates the use of inductive sensing technology to sense and measure the
presence or position of conductive target objects, and to detect the press of an inductive touch button. The
LDC is controlled by an MSP430, which interfaces to a host computer.
The LDC2112 is the two-channel version of the LDC2114. The LDC2112 does not have a dedicated EVM.
Instead, the four-channel LDC2114 EVM should be used to evaluate the technology and performance.
Figure 1. LDC2114 Evaluation Module
PCB perforations allow removal of the microcontroller, so that a different microcontroller can be
connected.
This user guide covers the following EVMs:
Table 1. List of Evaluation modules
EVM name EVM revision Device under test
LDC2114EVM A LDC2114 WCSP

www.ti.com Compatible Sensor EVM
7
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
2 Compatible Sensor EVM
The EVM does not include any example sensors, but can easily be connected to sensors by using either
the ZIF connector or soldering wires to the header pins on the PCB. The LDC2114 EVM is compatible
with the LDCCOILEVM, which is available on the TI estore and contains 19 different sensor designs.
Connect sensors from the LDCCOILEVM with unshielded twisted pair wires to J6 of the LDC2114 EVM.
NOTE: Schematics, Layout, and Coil characteristics of the LDCCOILEVM are described in the
LDCCOILEVM user guide.
Table 2 shows the connection options for each coil type.
Table 2. Connection options
LDCTOUCHCOMCOILEVM coil type Connect to
A J3 ZIF connector using flat ribbon cable
B J3 ZIF connector using flat ribbon cable
C J3 ZIF connector using flat ribbon cable
D J3 ZIF connector using flat ribbon cable
E J6 2.54mm header using unshielded twisted pair wires
NOTE: When connecting the coil board to the EVM, it is recommended to attach the assembly to a
static object using tape or screws. This will prevent the cables from moving and potentially
changing the output code reading or reporting false triggers.
3 Main EVM elements
Figure 2. Main EVM elements

Sensing Solutions EVM GUI www.ti.com
8SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
The EVM has the following features, as shown in Figure 2:
1. Power indication LED: this LED shows that the PCB is powered through the USB cable
2. MSP430 GPIO headers: This is a multi-purpose GPIO header which facilitates connection with a
second I2C interface, JTAG, UART, and three additional GPIOs. It also contains 5V, 3.3V, and GND
rails. These pins could be used for example to connect a haptics driver or an audio amplifier. Note that
functionality pof these pins is not implemented in the default EVM firmware.
3. Sensor capacitors: These are the sensor capacitors of the LDC2114. Replace them with suitable
values if appropriate.
4. Alternative connection for UTP cables: Custom sensors can be connected to these header
connections. Unshielded twisted pair (UTP) wires are the preferred wire choice for the sensor.
5. ZIF connector for LDCTOUCHCOMCOILEVM: Sensors of this PCB can be connected easily by
connecting the supplied flat ribbon cable.
6. BSL jumper connection: If firmware upgrade is unsuccessful, put the MSP430 into bootstrap loader
mode by shorting these two pins while powering up the EVM.
7. Micro-USB connector: connect to the PC using a micro-USB cable
8. Force touch LEDs: these eight LEDs show the intensity of the button press. They default firmware
chooses the channel with the strongest button push to indicate intensity.
9. MSP430 F5528: This microcontroller is used to configure the LDC2114, facilitate data streaming to the
GUI, and to show the intensity of the button press.
10. Perforation and probing header: These pads can be used for probing any signals between the
MSP430 and the LDC2114. It can be populated with a standard 2x11 pin 2.54mm header for ease of
access. It is also possible to break the LDC along the perforation and attach a different microcontroller
to these pins. The signals of the header are: [1-2]: OUT3, [3-4]: OUT2, [5-6]: OUT1, [7-8]: OUT0, [9-
10]: INTB, [11-12]: LPWRB, [13-14]: SDA, [15-16]: SCL, [17-18]: GND, [19-20]: +3.3V, [21-22]: GND.
Note that the signals on this header are referenced to the Microcontroller VIO voltage (3.3V).
11. Button Press LEDs: These LEDs indicate which button has been pressed. Note that the MAXWIN
function is not enabled by default, so multiple buttons can be pressed simultaneously, and therefore
multiple LEDs may light up.
12. LDC2114: The LDC2114 Inductive Touch Inductance-to-Digital Converter for Consumer and Low-
Power Applications
13. LDC probing pads: These probing points use the level-shifted (1.8V referenced) signals of SDA, SCL,
OUT0, OUT1, OUT2, and OUT3
4 Sensing Solutions EVM GUI
The Sensing Solutions EVM GUI provides direct device register access, user-friendly configuration, and
data streaming.
4.1 System Requirements
The host machine is required for device configuration and data streaming. The following steps are
necessary to prepare the EVM for the GUI:
• The GUI and EVM driver must be installed on a host computer.
• The EVM must be connected to a full speed USB port (USB 1.0 or above).
The Sensing Solutions EVM GUI supports the following operating systems (both 32-bit and 64-bit):
• Windows XP
• Windows 7
• Windows 8 and 8.1
• Windows 10

www.ti.com Sensing Solutions EVM GUI
9
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
4.2 Installation Instructions
The Sensing Solutions GUI and EVM driver installer is packaged in a zip file. Follow these steps to install
the software:
1. Download the latest version of the Sensing Solutions EVM GUI from EVM tool page.
NOTE: The minimum Sensing Solutions GUI revision for this EVM is 1.9.1. The latest GUI can be
downloaded here.
2. Extract the downloaded ZIP file.
3. Run the included executable.
4. If prompted by the User Account Control about making changes to the computer, click Yes.
Figure 3. User Account Control Prompt
5. After the setup wizard starts, click Next.

Sensing Solutions EVM GUI www.ti.com
10 SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 4. Software Installer Wizard
6. Read the license agreement, select I accept the agreement, and click Next.
Figure 5. Software Installer License Agreement

www.ti.com Sensing Solutions EVM GUI
11
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
7. Use the preselected installation directory and click Next.
Figure 6. Software Installation Directory
8. Start the installation by clicking Next.

Sensing Solutions EVM GUI www.ti.com
12 SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 7. Software Installer Ready
9. Wait for the installation to complete.
Figure 8. Software Installer in Progress

www.ti.com Sensing Solutions EVM GUI
13
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
10. When the Device Driver Installation Wizard appears, click Next to install the EVM driver.
Figure 9. Device Driver Installer Wizard
11. Wait for the driver installation to complete.

Sensing Solutions EVM GUI www.ti.com
14 SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 10. Device Driver Installer in Progress
12. After the driver installation is completed, click Finish.

www.ti.com Sensing Solutions EVM GUI
15
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 11. Device Driver Installer Completed
13. Click Finish to complete the installation.
Figure 12. Software Installer Completed

Sensing Solutions EVM GUI www.ti.com
16 SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
4.3 Starting the GUI
Follow these steps to start the GUI:
1. Select the Windows start menu.
2. Select All programs.
3. Select Texas Instruments.
4. Select Sensing Solutions EVM GU.
5. Click Sensing Solutions EVM GU.
6. The splash screen will appear for at least two seconds.
Figure 13. Splash Screen
7. After the splash screen is displayed the main window will open.

www.ti.com Sensing Solutions EVM GUI
17
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 14. Introduction Page
4.4 Navigating the GUI
To navigate to different pages of the GUI follow these steps:
1. Click Menu in the upper left corner.

Sensing Solutions EVM GUI www.ti.com
18 SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 15. Mouse Hovered Over Menu Button
2. Select the desired page from the menu shown on the left.
Figure 16. Menu Display After Clicking Button

www.ti.com Sensing Solutions EVM GUI
19
SNOU144–December 2016
Submit Documentation Feedback Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
4.5 Connecting the EVM
Follow these steps to connect the EVM to the GUI:
1. Attach the EVM to the computer through USB.
2. The GUI always shows the connection status on the bottom left corner of the GUI.
Figure 17. EVM Connected to GUI
4.6 Configuring the EVM Using the Register Page
The register page allows users to control the device directly with the register values. The user may also
use this page to read the current register values on the device.
4.6.1 Automatically Update GUI Register Values Using Auto Read
Auto read will periodically request the register values on the device. Click the drop down box next to Auto
Read to select the update interval.

Sensing Solutions EVM GUI www.ti.com
20 SNOU144–December 2016
Submit Documentation Feedback
Copyright © 2016, Texas Instruments Incorporated
LDC2114 Evaluation Module for Inductive Touch Inductance to Digital
Converter
Figure 18. Selecting Auto Read Interval on Register Page
4.6.2 Manually Update Device Register Values
There are two methods to change register values: update the entire register value or change a single bit
within the register. The recommended update mode is always Immediate and not Deferred. To update
register values, follow these steps.
1. Double-click the current value of the register that needs to be changed. The text will turn into an
editable text box.