please help me design a circuit on PIR sensor?

Question

the purpose is to design a circuit diagram for the PIR sensor to detect body temperature of a human being.and I am allowed to use any programming for this circuit.Please help to design a simple circuit diagram.I seriously need help on this.Thanks

the purpose is to design a circuit diagram for the PIR sensor to detect body temperature of a human being.and I am not allowed to use any programming for this circuit.Please help to design a simple circuit diagram.I seriously need help on this.Thanks

Answer 1

Take the analog output from the PIR sensor. Put this into a microcontroller with an Analog to Digital converter. Once you have this value, program the microcontroller to sample the analog input voltage. Sample this voltage periodically. Once you calibrate the values, you can simply say for a given analog voltage, the temperature should be this value. For what you need the relationship will be semi-linear because of the limited rage of body temperature, so you should calibrate using a known temp and analog voltage. Do this at your max temp and min temp expected then interpolate any in-between values. Feel free to ask more questions or post more information. Most likely you would get better results if you are detecting something from a small sensor, like a thumb sensor. If you detect an object from the wall or from far away, you could get size information probably more reliably than temperature information.

Sorry for the confusion. I thought you said you WERE allowed to program this. Are you detecting body temp or the presense of a body? (Do you need to detect a human or get their actual temperature?)

And what PIR sensor are you using? Have you picked one, yet?

Answer 2

Lot of circuit diagrams are available in application notes of national semiconductor's application notes. in any different case you could bypass to googles and kind IC 555 application notes and gets each and every of the producer's circuits and alertness notes. PWM with 555 is available.you're able to be able to ought to function one driving force and dc motor. in case you have a small dc motor then 555 itself can force yet extra appropriate to function a transistor buffer/driving force.