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Demonstrating a Wireless Link
Table 1. 4-Bit DIP Switch (SW1) Settings and Transmit Frequencies
(continued)
1234 SW1 Setting
TX Frequency (MHz)
RX Frequency (MHz)
(1=On, 0=Off)
4903 TX Board
6903 RX Board
0001
903.218
892.5184
0010
904.4468
893.7472
0011
905.266
894.5664
0100
906.0852
895.3856
0101
907.7236
897.024
0110
909.362
898.6624
0111
910.1812
899.4816
1000
911.8196
901.12
1001
912.6388
901.9392
1010
913.458
902.7584
1011
914.2772
903.5776
1100
915.506
904.8064
1101
916.3252
905.6256
1110
917.554
906.8544
1111
918.3732
907.6736
2.2.2
Power Up
Slide the power switch to ON. The STANDBY, MODE, and LOCK DETECT LED’s blink to indicate power
up condition. After the power-up initialization, the TRF4903 based transmit unit goes into Standby Mode
(IDLE_STATE) and Mode 0 and waits for a button press. This turns off all the LED’s.
Note:
The LOCK LED on the transmit board is connected to the multiplexed pin 16 of the
TRF4903. Initially, the TRF4903 is programmed to obtain a lock detect signal on the
multiplexed pin 16. This turns on the LOCK DETECT LED on the transmit board.
Once the TRF4903 is ready to transmit data, the multiplexed pin 16 is
programmed for the DCLK mode and the recovered data clock at 38.4 kbps is
output at terminal 16. This blinks the LOCK LED at 38.4 kbps. Once the
transmission is complete, the TRF4903 goes back to Standby (IDLE_STATE)
and the LOCK LED is turned off again.
The TRF6903 based receive board goes into the receive mode to monitor for any transmit activity. The
RSSI indicator LED is lighted to indicate the signal strength in the frequency channel of operation. Red
indicates the lowest signal strength and green indicates the highest.
2.2.3
Wireless Demonstration
Only the TRF4903 transmit board is configured to initiate wireless communication. Assume that Board A is
the transmit board and transmits the first four-button transmitted sequence and Board B receives the
transmission.
Use Board A to start the wireless demonstration by pressing the four colored buttons in any sequence with
about 1/2 second between successive buttons. Once the four buttons are pushed, Board A initiates the
transmission.
Once the transmission is received by Board B and if the response sequence matches, the LEDs are
turned on in the same sequence as the buttons were pushed at the transmitter side.
TRF4903 With MSP430 Demonstration and Development Evaluation Kit
6
SWRU010A – October 2004 – Revised May 2005