User's Guide
SCDU004 – March 2013
TCA8424 Evaluation Module
This document is the EVM user guide for the TCA8424. The device is a low-voltage keyboard scanner that
can support up to 128 keys, with open drain outputs that can sink up to 12 mA of current for LEDs. The
TCA8424 is fully HID over I
2
C™ compliant and is available with a pre-programmed keyboard map.
Contents
1
About this Manual
...........................................................................................................
2
2
Information about Cautions and Warnings
..............................................................................
2
3
FCC Warning
................................................................................................................
2
4
Items Required for Operation
.............................................................................................
3
5
Introduction
..................................................................................................................
3
6
TCA8424 EVM Design Circuitry, Bill of Materials, and Connection Descriptions
..................................
4
6.1
TCA8424 EVM Schematic
........................................................................................
4
6.2
Printed-Circuit Board (PCB) Layout
.............................................................................
5
6.3
Bill of Materials
.....................................................................................................
9
6.4
VCC and GND Connections
....................................................................................
11
6.5
MSP430 Launchpad Interface
..................................................................................
11
6.6
Breakout Pins
.....................................................................................................
12
6.7
LED Outputs
......................................................................................................
13
7
Launchpad Software Setup
..............................................................................................
14
8
GUI Software Setup
.......................................................................................................
16
9
GUI Walkthrough Guide
..................................................................................................
17
10
Related Documentation
...................................................................................................
30
List of Figures
1
TCA8424 EVM Schematic
.................................................................................................
4
2
Layer 1 Top Side: 50-
Ω
Signal Layer
....................................................................................
5
3
Layer 2 (Int1): Ground Plane
..............................................................................................
6
4
Layer 3 (Int2): 50-
Ω
Signal with Ground Fill
.............................................................................
7
5
Layer 4 Bottom Layer
......................................................................................................
8
6
VCC and GND Connections
.............................................................................................
11
7
MSP430 Launchpad Interface
...........................................................................................
11
8
Breakout Pins
..............................................................................................................
12
9
LED Outputs
...............................................................................................................
13
List of Tables
1
Bill of Materials
..............................................................................................................
9
2
Header Configurations for P1, P2, and P7
.............................................................................
12
1
SCDU004 – March 2013
TCA8424 Evaluation Module
Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated