Motion Sensor LED Lights - or do we think school work?

[LoneWolf]

Hi People, I am new to this website, and yes, got invited
anyways, so i am trying to put together a weekend project, my resources as of now are limited, so this is a rather simple and small project,  i want to build an array of LEDS that light up when a person gets close or anything that gets close to an infrared sensor or photodetector LED, i have a basic understanding of how the infrared sensor leds work, but i am not sure as how to integrate the sensor to the circuit, i built a circuit no long ago that uses a photosensor led, basically it turns on a couple of leds when there is no light, and turns off when there's light, the thing is that is not too sensitive, because of the angle on which the led senses the light is very narrow,  so i want to modify this and make a movement activated lamp, the basic idea is if a person gets close, the lights would turn on, if the person walks away, it would turn off, any ideas how to accomplish this?

[TucoRamirez]

something like that to trigger your leds ... (using a transistor to drive your array of leds off course)

[solutions]

Look up "PIR sensor"

[Catcatcat]

Idea No. 1 is my project on a conventional sensor Infrared motion sensor, PIR-sensor if you need more information, do not hesitate to ask questions.

The idea is to use the number 2 PIR-ins AM322 AM422 AM622 , here at all just add a potentiometer and a transistor for load control and the whole motion sensor

[pushycat]

Post/ Reply #11 on this below page link may be useful for you
Its a PIR module based motion sensor light, a circuit idea published in EFY magazine
http://www.sonsivri.to/forum/index.php?topic=33139.0

[LoneWolf]

thank you guys, useful info,  i recently talked to a friend of mine, he's a member of this site too, he suggested using ultrasonic sensors, but he said the only think is that it needs a minimum distance in order to work, but i was looking at the ultrasonic sensor used on arduinos, and seems to have the range i am looking for: http://www.amazon.com/Ultrasonic-Module-HC-SR04-Distance-Arduino/dp/B004U8TOE6/ref=sr_1_1?ie=UTF8&qid=1368044348&sr=8-1&keywords=ultrasonic+sensor

I will look into the PIR Sensors, but if i were to use the ultrasonic sensor, is there a way to control the parameters of the ultrasonic sensor analogically? meaning, being able to control an input/output function on the circuit without the need of a microcontroller?

UPDATE: i jacked one of my work's old alarm sensors, they were gonna throw it out anyways so is not really a steal, lol, anyways i cracked it open, i see the PIR sensor and the board components, now im gonna go grab some tools to test it out and see if i can change the parameters to adjust it to a closer distance

[Catcatcat]

The simplest solution is the modules AM322 AM422 AM622, if you use conventional PIR-sensor, type D203x - D205x, then you need another LM324 or BISS0001

[robotai]

Ultrasonic ranger module like HC-SR04 should be able to measure as short as couple centimeters. How short do you want to detect?

If simply use NE555 to generate pulse into input pin and keep detecting the output pin, you should be able to detect if anything in the range and turn your light on or off.