hi there,
am in need for some desperate help in this field with PIR sensors. have searched pir found some useful info but no luck
have purchased and rigged up a PIR sensor dual element from murata pdf at link below with fresnel lens. its just the bog standard sensor no amplification.
IRA-E700ST0 datasheet pdf datenblatt - Murata Manufacturing Co., Ltd. - Pyroelectric Infrared Sensors ::: ALLDATASHEET :::
i connected up to 5v supply from my 7805 and measured output using osc. am getting approx 1V output signal offset and the changes depending if sensor is passed from point a--b or b--a gives a voltage change +-15 mV. i need to connect this sensor to my PIC16f873a ADC pins an0 and an1 but the voltage change compared with the offset is negligible. i want to know how i can increase the voltage change so that i can compare the value with a Vref in the PIC when i use the ADC. if it is greater that ref voltage i know that someone has crossed from a-->b and if lower than vref i will know its b-->a thus being able to sense direction.
iam working on a lighting motion system model as a project to be used in corridoors
will be really grateful for all help on this matter best kaye![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
am in need for some desperate help in this field with PIR sensors. have searched pir found some useful info but no luck
have purchased and rigged up a PIR sensor dual element from murata pdf at link below with fresnel lens. its just the bog standard sensor no amplification.
IRA-E700ST0 datasheet pdf datenblatt - Murata Manufacturing Co., Ltd. - Pyroelectric Infrared Sensors ::: ALLDATASHEET :::
i connected up to 5v supply from my 7805 and measured output using osc. am getting approx 1V output signal offset and the changes depending if sensor is passed from point a--b or b--a gives a voltage change +-15 mV. i need to connect this sensor to my PIC16f873a ADC pins an0 and an1 but the voltage change compared with the offset is negligible. i want to know how i can increase the voltage change so that i can compare the value with a Vref in the PIC when i use the ADC. if it is greater that ref voltage i know that someone has crossed from a-->b and if lower than vref i will know its b-->a thus being able to sense direction.
iam working on a lighting motion system model as a project to be used in corridoors
will be really grateful for all help on this matter best kaye