priya

thnx once again.But sir,if i m modulating the IR then a normal photodiode wont be used as RXr.then i vill hav to use the TSOP wich is modulated at a frequency to which the IR is modulated i.e 38khz wich i have thought of.n the TSOP IC is black cased n i think it will act as daylight filter. cud plz guide me in this regard.

thanx If i think of modulating the ir signal at 38khz will that help in solving both the range n sunlight problem.besides this cud u plz tell me the circuit for the same.

i m using IR leds (without modulation) for the purpose of object detection along with a photodiode which is acting as a reciever for the IR Led and in addition to it the interruption in the ir transmitter RXr module is used to start a timer on. i m using a 555 timer in monostable mode n to the trigger pin of this i m connecting th photodiode n the output of this timer is given to a npn transistor and o/p of the transistor from collector is further given to the relay which gives ouput to the microcontroller.But im facing two problems .Firstly the range problem n secondly the TXr IR led n RXr