Application Note
Embedded Applications
Fixed Cellular Telephone
First edition (September 2004)
Sony Ericsson Mobile Communications. publishes this manual without
making any warranty as to the content contained herein. Further Sony
Ericsson Mobile Communications. reserves the right to make modifications,
additions and deletions to this manual due to typographical errors, inaccurate
information, or improvements to programs and/or equipment at any time and
without notice. Such changes will, nevertheless be incorporated into new
editions of this manual.
All rights reserved.
© Sony Ericsson Mobile Communications., 2004
EMBEDDED APPLICATIONS FCT
Contents
Contents.....................................................................................................3
1 Introduction ........................................................................................4
2 FCT design.......................................................................................... 5
2.1 Keypad ......................................................................................................5
2.1.1 Operation .......................................................................................5
2.1.2 Set-up ............................................................................................5
2.1.3 Keypad Configuration ....................................................................6
2.2 I
2
C LCD .....................................................................................................7
2.2.1 Operation .......................................................................................7
2.2.2 Set-up ............................................................................................7
2.3 Fixed Cellular Terminal Application {FCT.sc} ..........................................12
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EMBEDDED APPLICATIONS FCT
1 Introduction
When combined with the embedded applications scripting
language, interfacing a keypad and LCD to the radio
device can provide a simple man-machine interface
without the need for external host controllers.
This application note details the use the I2C interface for
the LCD screen and the intrinsic functions to control a 5 x
4 keypad matrix.
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EMBEDDED APPLICATIONS FCT
2 FCT design
Here an application of a fixed-cellular-terminal (FCT) is
used to illustrate the interfacing of a keypad and I
2
C LCD
to the radio device.
Application Block Diagram (Fixed cellular terminal)
2.1 Keypad
2.1.1 Operation
When the script executes it calls a key-scan routine in an
endless loop. When no key is pressed the key-scan
routine returns the code 0xFF. A key-press is detected
when any one of the KeyRow inputs receives a logic low.
The key-scan routine identifies which KeyColumn driver
was active when the key-press was detected and the
routine provides a return code representing the
combination of row and column.
2.1.2 Set-up
The keypad driver setup uses the function kyc() to define
which rows and columns are activated for the application.
This allows the user to select the most suitable keypad
size and avoids tying up control I/O which would be more
usefully applied elsewhere in the application.
This application example utilizes the full complement of
column drivers and row receivers to provide a 20 key
interface.
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