Looking for a short range motion sensor

Senne

Hi there,

is there a type of sensor that behaves like a computer mouse but only with a binary output? So zero when it's in range of an object but it's not moving, one when in range and moving and zero when out of range and moving. I would like to avoid the subassembly the sensor of a computer mouse has (LED and lens). The maximum range can be around 20-30 mm. Is there such a thing? Because so far I've only found sensor that basically only measure proximity but no actual movement. Thanks for your help guys!

Regards,

Senne

Duane Degn

So much of this is a big "it depends".

How much movement? Is the object a solid color? What is behind the object?

Changing the lens of a mouse does seem like a good plan. There are devices sold which use the camera of a mouse but make it easier to adapt the camera to other uses. In order to get the output to be either one or zero (high or low?), you'd probably need a microcontroller to read the mouse output and set the pin state high or low.

If a PIR sensor would work, it would be even easier to use since a PIR does set a pin high or low based on movement. PIR sensors are designed to sense changes in heat so it may not work for your application if the object and background are at the same temperature.

If you could give more information about the object (its size, color, shape, etc.) and more information about the background, we could probably give you a better answer as to which sensor to use.

It might be possible to use a few line following sensors to detect movement if the color of the object and background contrast significantly.

Publison

Not sure if this would work for you:

http://www.parallax.com/product/28046

With a little programming, I would suspect you can compare values to see if moment is detected.

Ron Czapala

Pololu sells a Sharp 10cm digital sensor that you might want to check out ​http://www.pololu.com/product/1134

or a 5cm version http://www.pololu.com/product/1131

Senne

Hi guys, thanks for the responses so far. You have to imagine the project like a computer mouse: so the sensor is fixed on the bottom of an object that is moved across a (mostly smooth) surface, the surface itself can have a uniform color and it can be pretty dark. So I'm not exactly trying to sense an object, I'm trying to sense the movement of the "mouse" itself across a surface (high). But when it's lifted from the surface, it should stop detecting, also when it stops but is still on the surface (low). Basically all the functionality of an optical mouse but with just a high-low reading instead of a relative position. I don't want the sensor to contact the surface so I cant really use the lens of a mouse, from a sligh distance maybe, but then I'd still have a bit of a bulky subassembly. Thanks!

Bill Henning

This should work for you:

http://www.mikronauts.com/sirmorph/

It is normally used with an analog input, however if you hook it up to a potentiometer, you can adjust the trigger point for a 3.3v I/O

Senne wrote: »

Hi guys, thanks for the responses so far. You have to imagine the project like a computer mouse: so the sensor is fixed on the bottom of an object that is moved across a (mostly smooth) surface, the surface itself can have a uniform color and it can be pretty dark. So I'm not exactly trying to sense an object, I'm trying to sense the movement of the "mouse" itself across a surface (high). But when it's lifted from the surface, it should stop detecting, also when it stops but is still on the surface (low). Basically all the functionality of an optical mouse but with just a high-low reading instead of a relative position. I don't want the sensor to contact the surface so I cant really use the lens of a mouse, from a sligh distance maybe, but then I'd still have a bit of a bulky subassembly. Thanks!