Texas Instruments TRF4903, User Manual, Page: 7 / 26

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3 Prototyping
3.1 Connecting to the MSP430 JTAG
Prototyping
If there are errors due to poor or lost transmission, NO LED lights up on the Board B. This concludes the
basic demonstration of the one-way RF communication.
On completion, the transmit board waits for another button press and the receive board goes back to
receive mode to listen for a new button sequence.
2.2.4 RSSI Indicator
Since the TRF4903 is a transmitter, it does not have an RSSI feature. The TRF6903 receive board is
equipped with a receive signal strength indicator (RSSI) that illustrates the signal strength on the receiver.
Four levels are used to indicate signal strength. Red is the lowest and means no signal was received,
while green indicates the highest level of signal strength. The RSSI shows transmission activity when the
other board is transmitting a data stream on the same DIP switch configuration or when there is another
external RF source broadcasting at that channel frequency. For the best results, the two boards should be
in the same plane of orientation, with the bend in the long antenna arm pointed towards each other.
2.2.5 Error Conditions
Cycle the system power to reinitialize the hardware if you get error conditions that persist. Error conditions
are defined as lost communication, mismatch in response sequences, or response time outs. In some
cases, antenna orientation, signal multipath, or another interfering signal can increase errors.
This chapter explains how to operate the MSP-TRF4903-DEMO kit to prototype new applications.
The MSP-TRF4903-DEMO is designed for rapid application development. The MSP430 MCU flash
memory can repeatedly be erased and reprogrammed. The on-chip emulation logic allows real-time
debugging and fast code development. The MSP-TRF4903-DEMO and the MSP430 flash emulation tool
provide everything that is required to develop an entire firmware project.
For information go to http://www.msp430.com
Connector J2 provides access to the JTAG port of the MSP430 microcontroller on the
MSP-TRF4903-DEMO circuit board. The MSP-FET430 flash emulation tool (FET) interface board
MSP-FETP430IF (not included in this kit) connects to J2 and allows real-time in-system emulation.
Programming the MSP430, assembler/C source-level debugging, single stepping, multiple hardware
breakpoints, full-speed operation, and peripheral access are fully supported in-system using the JTAG
connector.
Figure 2 shows the connections of the MSP-TRF4903-DEMO to the JTAG cable provided by
the MSP430 FET interface board.
TRF4903 With MSP430 Demonstration and Development Evaluation Kit SWRU010A – October 2004 – Revised May 2005 7