range finder

[epilot]

Hello,

is this possible making a range finder for targets more than hundred meters?
is there any circuit to be able to do that?

 

[dknguyen]

No

No. This is only within the range of companies and is out of the price range for the vast majority of individuals. It requires either lasers or radar and working with optical alignments, ultrafast timing circuitry, etc. Devices with the ranges you speak of and accuracies less than a foot (most of which are accurate to the mm) are $3000 with a giant price jump to $5000 then $10,000+.

The only practical option available to you (without hacking golf rangefinders which are pretty affordable)is one of the following (basically is like a stripped down golf-rangefinder with an RS-232 interface to use with a uC). They cost a bit more than the cheapest golf rangefinders though...but interface with a uC much more readily:
Opti-Logic RS100 Laser Rangefinder
Opti-Logic RS40 Laser Rangefinder
Opti-Logic RS80 Laser Rangefinder

The difference between them is different max ranges. 100, 400, and 800 yards (1 yard = 3ft = 0.91m). Minimum sensing range of 4 yards and accuracies of 1-2m. THe accuracy makes it useful only for long-range sensing. At closer ranges the error becomes too large to be useful.

If you were trying to save money...that's pretty much the end of it. The above is the only option I have found in my long long search that is less than $3000. But, what you are asking for is not an inexpensive thing.