Tagged Questions

3
votes
1answer
92 views

PIR sensor triggered by itself when using timer, works without timer

TL;DR A PIR sensor is triggered by itself when using a timer to wait 2 seconds after the sensor is triggered. Without using the timer to wait the sensor works as expected. Background and setup I ...
10
votes
6answers
577 views

Ideas to measure 2D position of an object constrained to X-Y plane

I am working on a project, and an aspect has come up where I would like to measure (track continuously) the X and Y position of an object across a 2D plane. The object is moved by a person, with the ...
2
votes
1answer
254 views

Detecting absolute position

I am working on project that requires me to detect the position of a pen on a piece of normal paper. My first thought was to use 4 IR LEDs on a receiving unit set at the top of the page, and to put ...
3
votes
5answers
2k views

Reducing the sensitivity of a PIR sensor?

I have several of these PIR sensors. I am hoping there might be a way to reduce range/sensitivity to a very small field. Currently they are detecting motion about 15-20 feet away. Does anyone know ...
4
votes
8answers
4k views

How to make IR proximity detector immune to the daylight?

I am trying to make an infrared proximity measurement device. I want it to be in the range of 10cm or 4" (maybe 15 cm?). The frequency I use is 10 KHz. Here is the circuit I used, except that I have ...
4
votes
3answers
2k views

Cheap effective proximity sensors for detecting people?

I'm building a small device that will be mounted on the ceiling (along with many other identical ones), facing downwards. I'd like to detect when someone walks underneath it. Due to the constraints of ...