User manual

MCP2030 BIDIRECTIONAL
COMMUNICATION DEMO KIT
USERS GUIDE
© 2006 Microchip Technology Inc. DS51637A-page 7
Chapter 2. System Overview
2.1 OVERVIEW
This section describes how to use the MCP2030 Bidirectional Communication Demo
Kit.
The MCP2030 Bidirectional Communication Demo Kit consists of two Transponders
and a Base Station unit. The Transponder consists of an MCP2030 (stand-alone
three-axis analog front-end device), a PIC16F636, and an MCP3421(18-bit
delta-sigma analog-to-digital converter). Unlike the existing PKE Reference Design
System (P/N: APGRD001) from Microchip Technology Inc., this Transponder uses
stand-alone devices for the bidirectional passive keyless entry (PKE) operation. This
system also demonstrates the received signal strength indicator (RSSI) function using
the MCP3421 delta-sigma ADC. When the Transponder receives a Base Station com-
mand, it transmits its ID and sampled RSSI value. By monitoring or mapping the RSSI
values, the user can estimate location or motion of the transponder with respect to the
Base Station unit. For example, for the automotive passive keyless entry (PKE) appli-
cations, the Base Station mounted inside the vehicle can determine whether the tran-
sponder is located inside or outside of the vehicle, or in the front or back seat in the
vehicle.
The Base Station unit consists of a PIC18F4680, a low frequency (LF) power amplifier,
an LF receiver section, a 434 MHz UHF receiver module, an LCD display, and
CAN/LIN transceiver sections. The components in the LF receiver section and the
CAN/LIN transceiver sections are populated on the PCB for future use, but their
functions are not utilized for this demo version. Any user who needs these features can
contact Microchip Technology Inc. for further information.
The MCP2030 Bidirectional Communication Demo Kit has been designed for easy
modification by customers. The firmware of both the Transponder and Base Station
units can be easily modified using the MPLAB
®
in-circuit serial programmers.
FIGURE 2-1: MCP2030 Bidirectional Communication System Block Diagram.
LED
434 MHz
Transmitter
MCU
LED
434 MHz AM
Receiver
LF
Transmitter/
Receiver
LF Command
(125 kHz)
Response
(UHF)
Ant. X
Ant. Y
Ant. Z
125 kHz
LC Series
Resonant Circuit
125 kHz
LC Parallel
Resonant Circuit
LCD
Analog Front-End
(MCP2030)
(PIC16F636)
ADC
(MCP3421)
Button
SW
Microcontroller
(PIC18F4680)
Base Station Transponder