Program Flow - Texas Instruments CC2545 User Manual

5.2.2 Program Flow

The PER test has two modes of operation, MASTER mode and REMOTE mode. The CC2543/45 can
run both modes while the CC2544 can only run the MASTER mode. This is because the CC2544 is
mounted on the CC2544 USB Dongle board which has no graphical user interfaces (required for
configuration of REMOTE mode operation). When the CC2544Dongle is powered up it automatically
enters MASTER mode and no further action is required from the user. In this section the PER test will
be explained for the CC2543EM mounted on the SmartRF05EB. The CC2545EM comes
preprogrammed with the same program and can be used the same way as the CC2543EM. The
Source code is also compatible with the CC2541EM (CC2541 in proprietary mode).
To get a quick walkthrough on how to set up the PER test refer to the "CC2543-CC2544DK Quick
Start Guide" [6]. A printed copy of this is included in the kit. The source code for the PER test can be
downloaded from the kit product page [8].
When the preloaded PER test is running on the CC2543EM (mounted on the SmartRF05EB) the user
will be presented with a choice between the two modes of operation (MASTER and REMOTE). The
operations of these two modes are presented below.
5.2.2.1 MASTER Mode
When a device enters the MASTER mode it can be described as a MASTER device. When this mode
is started the program enters the state called "masterBeaconMode". In this state the device configures
the radio in a default state (Modulation: GFSK, Data rate: 250kbps, Frequency: 2402 MHz) and starts
transmitting a beacon packet every 10 milliseconds. After every transmitted packet the MASTER
device listens for an acknowledgement packet containing configuration settings for a new PER test. If
this configuration packet is received, the MASTER device reads out the packet content and then
enters the "masterTxMode" state. In this state the radio is configured according the settings given in
the configuration packet. Then the radio starts transmitting the given number of packets at an interval
of 10 milliseconds. For every sent packet the REMOTE device will send an empty acknowledgement.
If the MASTER device receives these acknowledgements the bottom line on the LCD display will state
the following status: "Remote: ONLINE". If the MASTER device does not receive these
acknowledgments the bottom line will show: "Remote: OFFLINE". After the MASTER device is finished
transmitting all the packets, it will go back to the "masterBeaconMode" state and send a beacon
packet every 10 millisecond.
5.2.2.2 REMOTE Mode
When a device enters the REMOTE mode it can be described as a REMOTE device. When this mode
is started the program queries the user for a PER test configuration. It will ask the user to choose the
frequency, modulation type, packet length, number of packets to be sent and LNA gain (Only for data
rates ≠ 2Mpbs). All of these options will be stored in an array called "ackConfig". The joystick (U1) and
button1 (S1) on the SmartRF05EB are used to change and select the different options for the test
configuration.
After the choices have been completed by the user, the program enters the state called
"remoteSetupMode". In this state the REMOTE device configures the radio in a default state
(Modulation: GFSK, Data rate: 250kbps, Frequency: 2402 MHz) and starts to listen for beacon
packets from a MASTER device. If it receives a beacon packet, the REMOTE device will transmit an
acknowledgement containing the information previously stored in the "ackConfig" array. It will repeat
this whole process for 100 milliseconds in case the MASTER device does not receive some of the
initial acknowledgement packets. If it has not received a beacon packet and transmitted an
acknowledgement within 100 milliseconds, the LCD will display the following message: "No Beacon
Signal". The user can then choose to retry by pushing button1 on the SmartRF05EB or to set up a
new test by pushing the joystick (U1) up and then pressing button1(S1).
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