User manual

MCP2030 Bidirectional Communication Demo Kit User’s Guide
DS51637A-page 8 © 2006 Microchip Technology Inc.
2.2 OPERATIONAL OVERVIEW
When the MCP2030 Base Station unit is powered on using a 9 V power supply and the
MCP2030 transponder demo board is powered-on using a 3V lithium battery, the
system works as follows:
(a) The Base Station unit transmits an LF command. Requesting the Transponder’s ID
and RSSI data.
(b) When the Transponder receives the LF command, it transmits its 32-bit ID and RSSI
data via the UHF (434 MHz) link.
(c) When the Base Station unit receives the response from the Transponder, it displays
the Transponder ID and RSSI value on the LCD.
(d) The system repeats steps (a) through (c) as long as the power is supplied.
(e) If the button switch SW3 or SW4 on the Transponder is pressed, the Transponder
transmits the button data (SW3: Unlock door, SW4: Lock door). The Base Station unit
displays the button message on the LCD.
Figure 2-2 shows the communication sequence between the Base Station and the
Transponder units. Figure 2-3 shows the Base Station’s LF command and the
demodulated data by the MCP2030.
FIGURE 2-2: Base Station Command and Transponder Response.
10 bit LF Command
Continuous LF for
RSSI Sample
from Base Station
Demodulated data output
from MCP2030
Command to
a Soft Reset
MCP2030
MCU Sends
values
MCP3421
converts
RSSI to digital
ADC conversion
Completed here
Transponder Data Stream:
Header + 32 ID bits + 16 RSSI bits + 6 Parity bits + Stop bit
= Header + 54 Data bits + 1 Stop bit
at pin 9
of U1
at pin 3
of U3
at pin 8
of U3
at pin 5
of U3
Change back
MCP2030 configuration
register for
demodulated output