Remote device control using Radio Frequency


The project compares the communication of control signals using radio frequency
and Infra Red Rays. The STR is ideal for short-range remote control applications where
cost is a primary concern. The receiver module requires no external RF components
except for the antenna. It generates virtually no emissions, making FCC and ETSI
approvals easy. The super-regenerative design exhibits exceptional sensitivity at a very
low cost. A SAW filter can be added to the antenna input to improve selectivity for
applications that require robust performance. The manufacturing-friendly SIP style
package and low-cost make the STR suitable for high volume applications.
The STR-315 uses a super-regenerative AM detector to demodulate the incoming
AM carrier. A super-regenerative detector is a gain stage with positive feedback greater
than unity so that it oscillates.
The received signals can be decoded using a standard ST-12 decoder chip. A 89C51
micro controller from atmel is used to generate the control signals at the transmitter side.