Application Note: JN5121 Wireless Microcontroller
JN-AN-1006
Packet Error Rate Testing
Author
Ian Morris
JN-AN-1006 (v2.0) 31-Aug-2006 © Jennic 2006 1
Introduction
This application note illustrates Packet Error Rate (PER) testing using the JN5121 Evaluation
Kit. PER testing can be used to evaluate the communication range achievable in different
operating environments.
The attached binary files should be loaded into two of the boards contained within the
Evaluation Kit, testing can then be performed by following the operating instructions as
described below.
Installation
The file PerMaster.bin can be installed on any type of board, although to change between
‘acknowledged frames’ and ‘no acknowledge’ mode requires the extra buttons that are only
provided on a controller board (one with the LCD panel). Results are output on the serial port
and, if the file is installed on a controller board, the results are displayed on the LCD panel as
well. The file PerSlave.bin can be installed on any type of board.
To display results via the serial port use HyperTerminal or similar, set to a baud rate of 38400, 8
bits, no parity, 1 stop bit, no flow control.
NOTE: HyperTerminal sets the RTS line on the serial port, which we normally use when the
chip is booted to set the device into programming mode. Hence, you must either unplug the
cable whilst switching on, or click the option in HyperTerminal to disconnect the connection
whilst switching the board on, or use a different terminal program.
Operating Instructions
The packet error rate tester works by sending frames between the devices. It is possible to
select any of the available channels for testing. Also, there are two modes of operation, ‘no ack’
or ‘ack’. The default mode is ‘ack’ and the default channel is channel 14.
To move between ‘ack’ and ‘no ack’ mode, press button SW3 on the PerMaster board. In ‘ack’
mode, LED D2 will illuminate on the PerSlave board, and the mode will be shown as ‘ack’ on the
PerMaster board, on the LCD panel and through the serial port.
The channel number on both boards can be incremented by pressing button SW1 on the
PerMaster board. If the channel number is incremented past channel 26, it goes back to
channel 11.
