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Topic: Photo-electric sensor question (Read 750 times) previous topic - next topic

ultrablaze

Hello,

I'm working on a robotics project with my engineering school for a robotics competition, and part of it is re-using parts and devices left over from previous years. We have found a photo-electric sensor that we have been told worked last year, but we are not sure how to use it.

This is the datasheet : http://tinyurl.com/pkrcpon

We are not sure how to hook up the 3 cables we have ( see attachment) or how it works. We assumed the red and black connectors with tubing at the end were the 12-24V and mass, and the other was a digital input. As far as we  know its an all or nothing sensor, in that if there is a reflective material in the 3m range we should get 1 and otherwise 0. But it could be some completely different way, we are having trouble finding anyone discussing such a device online.

We tried it like this, and while we see it is emitting an infrared light we are unable to get any data from the sensor. We are interfacing with an arduino mega2560. For this kind of sensor, should the sensor pin hooked up to a digital input with a common mass between the devices be enough?

Thanks for any help, we really need to get it to work we don't have the budget to buy a new one.

Grumpy_Mike

Quote
with a common mass between the devices

What is a common mass?

Normally these sort of things are open collector, however that data sheet is hardly worth the name data sheet and what little it does say is "output PNP" which is odd.

Try just wiring it up by itself first, that is not to an arduino until you get it going.

Wire up the red and black to the power then measure the output (other wire ) with a meter. If you see nothing then wire a resistor of about 4K7 to the +ve line and the output and try again.
If still nothing then wire the resistor from the output to the -ve supply and measure again.

Good luck.

michinyon

It looks like an odd device .   Is is mounted on top of a servo ?

I am curious how you can see it is emitting an I/R light ?   Do you have bee-vision now ?   A photo-electric sensor does not normally have to emit any light of it's own,   unless it is a distance sensor,  or want to "see in the dark",  or wants to detect interruption of it's own light beam,   in which case the light source is mounted somewhere other than the detector (  for example,  a shop door customer detector ). 

A lot of these "industrial" devices have perversely un-informative information about what the device actually does.

If you think you can identify the power supply and ground wires,  hook them up and then see what the third wire does.  Use your multimeter.  With luck,  it may be obvious. 

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