IR sensor??

retched

Joined Dec 5, 2009
5,207
Im going to give you the benefit of the doubt and guess you have vision problems, If you have problems reading, tell me and Ill make my text HUGE like yours.

On to your other problem:

5th one down, on the linked page has standard TTL digital output.
http://www.futurlec.com/PIR_Sensors.shtml

The others on the top of the page, and the one you linked to, use an analog output that you will need an Analog to Digital Converter to get the output to a digital signal for use in digital circuits.

If you are using a microcontroller, see if it has a built in ADC.
 

jpanhalt

Joined Jan 18, 2008
11,087
Retched, I think the OP wants to measure distance, not use PIR for security.

In answer to the question, that group of sensors uses triangulation and gives analog output. They have been used for several projects discussed on the forum. Just be sure your obstacle reflects IR light.

I have not seen one that gives digital output directly, but have not done an exhaustive search on that aspect.

John
 

Thread Starter

A_Mousa

Joined Mar 14, 2010
8
thanks for both of u
@retched : :D:D

but in case of analog output :
will i take the output then connect it directly to ADC then to micro-controller (i will use pic 16f877a) or i need signal conditioning and other interfacing between them??
 

retched

Joined Dec 5, 2009
5,207
no.. You may consider a buffer, but I see no reason for that.

You can hook the output to the ADC inputs on the 16f877a.

The 16f877a has built in 10bit ADC. So thats all you need is the 16f877a and the sensor.

If you need more than 10bit resolution, you would need an external ADC.

Then it would be sensor out, to ADC in, then
ADC out to 16f877a in.
 

Thread Starter

A_Mousa

Joined Mar 14, 2010
8
but the problem is that IR sensor have a non-linear relation between the distance and voltage so if i connect it directly to ADC it will give wrong results
, so what shall i do to solve this?
 

jpanhalt

Joined Jan 18, 2008
11,087
Top