circumference of shell

Thread Starter

neepa

Joined Oct 7, 2016
3
Let me add some details in my question to elaborate what I am asking for - The idea is to measure the vertical and horizontal distance traveled by the mouse without the screen size limitation. I have a wireless mouse which can move freely in any direction within 10-15 feet range. I want to use this advantage to measure any distance. I know I can map the maximum range of my mouse on my screen and can do that but I don't even want range of the mouse to be the constraint while measuring the distance. Do I need raw mouse data to do this?

Edit: Example - : What I am trying to do is measure the real world circumference using mouse. Let say I have to measure the dimension of a shell then I would just move my mouse on the shell and it will register the dimension.

Few points to conclude the question

  1. Can we use mouse to measure the distance?

  2. Can we do it without modifying the mouse?

  3. Since mouse cursor can't move beyond the screen it is difficult to measure the x,y coordinate, Isn't it?

  4. Mapping the real world distance to screen is one solution but I don't want to that because it constraints it ability to measure the distance.

  5. Can we move the mouse beyond the screen?

  6. If we can, can we get the mouseX or mouseY location ?
 

jpanhalt

Joined Jan 18, 2008
11,087
The mouse attached to my PC is sensitive to acceleration. That is, if if I move it quickly over the same distance, the cursor moves more. Will that enhancement affect your use as a measuring device?

John
 

Thread Starter

neepa

Joined Oct 7, 2016
3
my system has to measure the circumference of any circular/elliptical shaped object which is larger in size.
how it can be done?
 

jpanhalt

Joined Jan 18, 2008
11,087
I think you missed my point about mouse movement that accelerates. How can you measure distance accurately, if the (edit: observed) output of the mouse varies with the speed (not just distance) with which you move it. That is, if you move it 2 cm slowly, you get one output. If you move it 2 cm quickly, you get another output.

Using that type of mouse (laser/LED, wireless) to measure distance across a surface will depend on the speed of movement and probably in the surface roughness too.

Now, if you have a good ball tracking mouse that does not have acceleration, then your proposal might work. There are already available devices for doing that that depend on the movement of a wheel.

Here is a link to one such wheel distance measuring device: http://www.draftingsteals.com/20625.html?gclid=COSk6obRidACFcEmhgoddeoP9Q

John
 
Last edited:

Thread Starter

neepa

Joined Oct 7, 2016
3
Thanks john for your guidance.

i can understand about this drawback.
can i use encoder for measuring displacement.
There are so many encoders available in market.
what type can i use? the output of encoder can be used to measure length?
 

jpanhalt

Joined Jan 18, 2008
11,087
Can encoders be used in a device to measure length? Yes.

For more specific help, you need to present a design with some specifics.

John
 

AlbertHall

Joined Jun 4, 2014
12,384
I believe that the mouse 'acceleration' is done by the software not by the mouse itself.
Search for 'read mouse position low level'. You may find a solution there.
 

John P

Joined Oct 14, 2008
2,026
If you were writing your own software, there is a WIndows command which positions the mouse cursor on the screen. Using that, you could define a central rectangle and reposition the mouse to the far side every time it crossed the rectangle's boundary. Then to measure a large distance, you'd have to count the number of times the mouse traveled the length or width of the rectangle. This cursor-acceleration feature would have to be off, of course!
 
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