i am having a problem detecting output changes from a PIR sensor module that is connected to a PIC, when the PIC detects the output changes it is suppose to respond by flashing an LED.
I measured the voltage and it was constantly outputting 64mV which i think is too small for a PIC to detect. I have heard that an Op-Amp is required to increase the voltage so the PIC can detect it.
I am not sure how to configure the op-amp and what mode of operation it should be in.
Please can anyone help me.
Surely a PIR sensor module outputs a logic level of some kind, to activate a relay or something similar?. Do you have something different?, or have you connected it wrongly?.
the output is connected directly to the port of a PIC. i have been putting my hand directly in front of it and havent seen any output changes. i thought because the voltage output level was so small that you couldnt tell the differance and thats where an amplifier came in.
Do you have a part name or a datasheet for your sensor? The manufacturers usually provide schematics including the amplifier stages.
As susggested, a PIR sensor module is far easier to use, as its output is TTL compatible.
You still give no clue as to what you have, a PIR module normally has a logic output of some kind, to feed a relay or an alarm system - are you wiring it incorrectly?, or do you have something different?.
Got it working today!
It was just a simple program code error. i had configured the PORT in the microcontroller that the sensor was connected to incorrectly.