Laser Sensor interface with uC for distance measurement

Please let me know I want to build distance measure device for 2m to 4m by using Laser.

Can anyone interested to tell me?

It is not clear what you are asking.

Thank you for reply,

Dear I want to build circuit for measuring accurate distance 1 meter to 4 meter by using LASER, ultrasonic sensor or IR Sensor,

which of the more suitable for distance finding and I can program uC ATmega,PIC and Atmel 89c52.

I'd recommend ultrasonic for that range.

What is the accuracy you are wanting ? The 3 methods will have different accuracy capabilities, and also very different complexity issues.

Thank you for reply,

Dear, the sensor should sense distance of min. 1 milimeter and max 4 meter or max 4m meter not necessary 1 meter max is ok.

imranahmed said:

Thank you for reply,

Dear, the sensor should sense distance of min. 1 milimeter and max 4 meter or max 4m meter not necessary 1 meter max is ok.

Click to expand...

1 mm ? Is that an accuracy requirement, or is it the minimum distance requirement ?

If its the former, then you have to use Laser, maybe IR. But cannot use ultrasound.
If its the latter then its a big problem using any of these methods i think.

Try to have clarity what you require. Only then a proper method can be chosen/ designed. And do not overpush your specs.

As I understand you need to 4 meter distance to be measured with 1 mm resolution I will recommend to you to use pulsed laser concept if target is reflective ...... I mean pulse laser with some finite time and and detect the counts for known distance for finite period then you can use the same logic for change in distance.... kindly note this approach works only if the movement of target happens after the counting time is completed..... I hope you can fine tune the procedure... I had used it and it works ...... now to talk about IR this will also work but in case IR you need to have but stable IR radiation control system problem is IR radiation is it decays in the powers for such long distance like 4m so accuracy will be concern.... I had never worked on ultrasonic approach .....but like to learn for u guys....please share your experiences with ultrasonic sensor for distance measurements

Good Luck

Thank you for reply dear,

Yes, you are understand my concept but I could not explain clearly sorry for that, I did not use ultrasonic sensor but I want to make
this distance finder and please explain me more or refer any link for pulse laser concept.

Laser Range Finder MkII
http://letsmakerobots.com/node/2989

PIC sonar (ultrasonic) range finding project using a seven segment display
http://www.best-microcontroller-projects.com/pic-sonar.html

Ultrasonic range finder using 8051
http://www.circuitstoday.com/ultrasonic-range-finder-using-8051


Best regards,
Peter

milind.a.kulkarni said:

As .....pulse laser with some finite time and and detect the counts for known distance for finite period then you can use the same logic for change in distance.... Good Luck

Click to expand...

This will not be feasible or practical for the OP. Try not to misguide, and instead try to give recommendations in keeping with the spirit & level of the asker.

cheers!

@kripacharya,
I am not able to understand your concern..... I had just said the flashing light concept for distance measurement where reflective target movement time is greater than the detection time where detector and reflective target must be in single direction and beam receive path must be maintained using two 45-90-45 prism.... However I respect your views......if you fell I had said some thing wrong please let me know....I will like to learn too

@peter do you see any conceptual mistake in the approach proposed

With regards,

Milind

milind.a.kulkarni said:

... distance measurement where reflective target movement time is greater than the detection time where detector and reflective target must be in single direction and beam receive path must be maintained ...

Click to expand...

It's not wrong per se, imho it's just a little too vague on quite complex issues which are very casually mentioned. Light travels a distance of 1 meter in around 3.3 nS.
A 1 mm accuracy requires the ability to measure time differences of better than 3.33 pico Seconds.

I get the impression that the OP does NOT have the wherewithall to either understand, undertake or implement a project with such numbers involved.

Hence my comment.

good luck & cheers!