I need electronic items to perform the following: a small portable device that can detect when a second portable device is out of a set range.
Hi douglas911,
I am not really sure what you are trying to do here. Can you elaborate a bit on what specific range measurement you are trying to do? Are you trying to do a visual measurement between to objects in a 2D plane or trying to do something where you need two objects reporting their position in relation to the other?
The products we have that are relevant to this forum are best suited for measuring the distance between the sensor and an object it is directed at. If you are not sure what type of distance sensor you want to use, I would recommend reading through our [Distance Sensing Guide. That will go over the various types of visual distance sensors we carry and the benefits/drawbacks of each type.
If you can provide additional information on what kind of distance measurements you are trying to get, we would be happy to provide suggestions for any products we carry that could work for your project.](https://www.sparkfun.com/distance_sensing)