Texas Instruments CC900DB, Руководство пользователя, Страница: 4 / 20

SWRU064
4
2 CC900DB Demonstration Board
2.1 Before starting
The CC900DB runs on a 3.6V Lithium battery. If the battery is not mounted and
soldered to the board, insert the battery at the rear side of the board. Observe the LED. If
the LED is turned on continuously, push the “ON” button. For proper operation the LED
shall be pulsing with a period of approximately one second. If not, remove the battery
shortly and reconnect. The battery terminals should be soldered for proper operation.
Important: Be sure not to short-circuit the battery terminals during soldering or at any
point of use.
Before using the CC900DB: The use of radio transceivers is regulated by international
and national rules. Before transmitting a RF signal, please contact your local
telecommunication authorities to check if you are licensed to operate the transceiver.
2.2 Demonstrator operation
The CC900DB demonstrate a very simple two-way remote control system.
To “wake” the module from power-down mode, simply press the “ON” button for a
short time. The LED will then start blinking with a period of approximately 1 second.
This is the “heart-beat” that shows the module is operating. During the short time the
LED is lit, the module is in active receive mode, and listens for a data packet. If a data
packet is not found, it goes to a “rest” mode for approximately 1 second. Hence, the
module listens for a data packet every second. This polled receiver algorithm is
implemented in order to save battery power.
Both modules should be enabled before a successful transmission can take place. A
transmission is initiated by pushing the “TX” button. A data packet of approximately 1.5
second duration is then transmitted. The data packet consists of a long pre-amble and a
short data field. The preamble is longer that 1 second to ensure that the transmission
intercepts with the polled receiver.
The data packet transmitted consists of a blinking sequence of approximately 2 seconds
duration, and will be shown on the receiver’s LED if the data packet was received free
or errors. The same “message” with an acknowledgement flag is then returned from the
receiver to the initial transmitter. Again, the blinking sequence will be shown on the
LED as a receipt acknowledge.