LSQ976-NR-1-0-20-R18 datasheet(32/50 Pages) MICROCHIP

32 / 50 page

Wireless Security Remote Control Development Kit User’s Guide

DS41646A-page 32

 2012 Microchip Technology Inc.

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.

LSQ976-NR-1-0-20-R18 Datasheet(PDF) 32 Page - Microchip Technology