I'm looking to be able to detect small products on a shelf. For example lipsticks or mascara which are small items. I'm looking for sensors that I could put on the shelf to detect the presence of those objects whether it is by distance, contact, weight, pressure. Although I need the sensors to be tiny. Is there somebody who knows where to point me to find such small sensor that could do the above?
Also, I would probably need many of those sensors for one shelf, would that be a problem? Is there a limit of sensors we can use in an arduino project?
Sorry if those questions are very basic. I just read on Arduino and looks something very interesting, I'd like to try it out!
An example would be able to detect product such as cosmetics on a store shelf such as lipstick, mascara, cream, etc. These objects are quite small. I'd like to know when an object is taken from the shelf or put back on the shelf. For this I could use a distance sensor from the back and by determining the variation of distance, I can determine whether an object has been taken. Or I could maybe use contact sensor so if the product doesn't touch the sensor I know it has been taken.
I'm not sure what would be the best type of sensor for this. I'd like something small that would be able to handle the size of products.
Let me know if you need more precision, I'd be happy to provide additional information needed.
What is the ultimate purpose? preventing thievery or something?
Are those items testers? If so here's an idea without sensors and probably much cheaper: wrap a small conductor around items and prepare special cases for them which closes circuit loop when items are intact with cases.
If you can modify the shelves the most reliable way would be to insert photo transistors under each object. They are very small but there would be a lot of wiring and the results would not be easy to change if the product size changes.
I doubt distance sensors will be focused enough and will read the neighbouring objects.
How many objects/shelves/etc are we talking about?
If you are interested in whether the shelf is touched perhaps use a microphone or piezo element attached to the shelf? Threshold detection will catch "interesting" events. Piezo element used as a knock-sensor might be best, I think it will be less sensitive to sounds in the air. Experiment with how to fix element to the shelf for best sensitivity.