Radio Board Configuration
When a DR-TRC105 radio board is initially power on, it is configured as follows:
Operating Frequency:
DR-TRC105-304-EV 303.825 MHz
DR-TRC105-315-EV 315.000 MHz
DR-TRC105-345-EV 345.000 MHz
DR-TRC105-372-EV 372.250 MHz
DR-TRC105-390-EV 390.000 MHz
DR-TRC105-403-EV 403.500 MHz
DR-TRC105-434-EV 433.920 MHz
DR-TRC105-450-EV 450.000 MHz
Power: +10 dBm
Frequency Deviation: ±50 kHz
Data Rate: 25 kb/s
Receiver Baseband Bandwidth: 100 kHz
The radio board is also initially configured in Receive Continuou s Mode (see the
TRC105 datasheet for an explanation of continuous data mode, buffered data mode,
packet data mode, etc.). In receive continuous mode, the MODE LED will be green.
Receive continuous mode allows the user to connect a modulated signal from an RF
signal generator onto the board through a short coaxial cable and verify the demod-
ulated signal with an oscilloscope at the DAT pin.
Briefly pressing the MODE button once configures the board into Transmit Continuous
Mode. The Mode LED will change color from green to yellow. This mode turns on the
transmitter. The frequency and output power may be verified with a spectrum analyzer.
A square-wave modulating signal may be applied to the DAT pin and the spectrum
observed on a spectrum analyzer.
Briefly pressing the MODE button again configures the board into Sleep Mode. The
Mode LED will turn off. By connecting an ammeter across the term inals of J1, with the
jumper removed, the user can ve rify the very low sleep current of the TRC105 device.
As shown in Figure 4, potentiometer R7 can be used to adjust the transmit power level.
To increase the output power, rotate the potentiometer screw clockwise. To decrease
the power, rotate the potentiometer screw counterclockwise. The transmit power is
divided into 8 levels. Adjusting R7 adjusts the voltage level to the A-to-D converter
(ADC) in the host microcontroller. The microcontroller periodically samples R7 for a
change, and updates the transmit power register when it detects a change in voltage
level. Each time the microprocessor updates the transmit power register the SPI LED
will flash indicating an SPI write.
©2010-2015 by Murata Electronics N.A., Inc.
DR-TRC105-DK User's Guide11/23/15