Wireless Security Remote Control Development Kit User’s Guide
The Microchip RKE demo uses PWM, driven by interrupt, in data whitening procedure.
The transmission data rate over the air that can be achieved is tightly related to the
operation speed of the microcontroller. Higher data rate requires faster processing
speed. Higher transmission data rate may reduce the total active time for each
transmission; however, higher microcontroller processing speed generally has more
current consumption. The real application may need compromise between higher data
rate and faster processing speed to get the optimal battery life.
6.3
DEVELOPING WITH THE EMBEDDED SECURITY DEVELOPMENT BOARD
AS RECEIVER
The Embedded Security Development Board acts as a receiver in the Wireless
Security Remote Control Development Kit. The target application microcontroller on
the right side of the development board is the driving host for the receiver. All data
receiving and KEELOQ security functionalities are performed by the target application
microcontroller. On the other hand, the host microcontroller is mainly used to drive the
LCD display in this demo.
If the developer decides to develop the application on the target application
microcontroller only, intercommunication between the target application and host
microcontrollers can be ignored. The prototyping area under the four push buttons for
target application controller can be used to prototype the application.
Same as the transmitter, when continuous mode is used to receive data, the data rate
is tightly associated with the processing speed of the microcontroller. Unlike the
transmitter, which is usually powered by battery, the receiving side usually is powered
by mains power, and power consumption is of less concern. It is possible to run the
microcontroller faster to compensate higher data rate.
On the other hand, if the developer decides to use the host microcontroller too, then
the intercommunication between the two microcontrollers may need attention. The host
microcontroller is an SPI slave, and thus requires faster response to the SPI command.
Generally speaking, if no SPI delay is applied by the target application controller side,
the operation speed of the host microcontroller needs to be double that of the target
application microcontroller.
DS41646A-page 32
2012 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
