IR proximity sensor design

Hello,

I want to design a Low cost IR proximity sensor. I have tried a normal circuit from internet and achieved a range of about 3- 4 cms. I want to acheive a range of about 1.5 metres. so I have decided to pulse the signal at a particular frequency.

I have decided to pulse the signal at 56khz. I would do this at the transmitter side using a pic mcu. But at the receiver side i have tried using a tsop4856 Ir sensor. But i would like to design a circuit of my own using a normal Ir photodiode or Photoresistor. I checked the tsop sensor datasheet and found that it uses a bandpass filter and an amplifier to allow and amplify only 56 khz signals. I am not sure about the calculations and design of a circuit at receiver end to acheive my task.

I have attached a circuit diagram which i found in internet with 10khz band pass. I dont know if this is correct . If so, which values should i change to get a bandpass at 56khz and why. It would be very helpfull if someone could explain the circuit as well.
I am a beginner in this field and technically this is my first project on my own. I want to learn by doing.Any kind of help would be appreciated.

Regards and Thanks

You can use TSOP17 INFRARED receiver module and an ir led with 38khz pwm. place both in front.
You can set the sence range to 1 foot.
Goggle search will give you working circuit also.

deepeshmishra said:

You can use TSOP17 INFRARED receiver module and an ir led with 38khz pwm.

Click to expand...

I am using 56khz frequency for my transmission and i have already tried with the TSOP module. But i would like to build a circuit with BPF using a simple photodiode or phototransistor.