Here in this project we are going to control the street automatically. Here we utilize the most popular invisible light IR (Infra Red) rays to sense the visitors. For bidirectional operation we employ two IR detector and IR emitter circuit.
When the person enter into the first IR, at the time street light will be automatically switched on. When the person enter into the second IR street light will be automatically switched off.
This IR emitter is switched in 30 to 40 KHz for proper sensing operation. Infrared is an energy radiation with a frequency below our eyes sensitivity. This infrared can use for communication purpose but it has lot of disadvantages due to the interference of other infrared sources. So to avoid such interferences we switch the emitter in 30 to 40 KHz.
This switching frequency is generated by the microcontroller AT89s52. This same microcontroller will receive the pulse from the detector circuit and display the corresponding counts in the 7 segment display. These receiver circuits consist of IR detector diode with the comparator