Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: ultrablaze on March 06, 2014, 09:48:36 AM

Title: Photo-electric sensor question
Post by: ultrablaze on March 06, 2014, 09:48:36 AM
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 (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 an analog signal. 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.

Thanks for any help, we really need to get it to work we don't have the budget to buy a new one.
Title: Re: Photo-electric sensor question
Post by: jwatte on March 06, 2014, 11:19:17 AM
From the data sheet, it looks like an on/off switch. Try checking the resistance between the third lead and ground when it's "on" and when it's "off." Range seems to be up to 3m, so pointing it out into a big nowhere might be a good way to turn it "off."

Title: Re: Photo-electric sensor question
Post by: Tommy on March 06, 2014, 06:12:32 PM
If the manufacture followed the industrial standard for proximity switches.

Brown = 24V
Black   = 0V
Blue = N/O or N/C contacts

For NPN type Blue supplies 0V
For PNP type Blue supplies 24V



Tommy
Title: Re: Photo-electric sensor question
Post by: ultrablaze on March 07, 2014, 06:30:01 AM
Tried mesuring resistance when it was off or on, seems identical in both cases. I've confirmed it is not an analog sensor like I first thought, it just gives a binary 0/1 based on whether id detects something in range or not. I'm using it with an arduino so I was hoping I'd be able to just hook it up to a digital input pin and use digitalRead and get a 0 or 1 depending on when it's blocked or not.

I get a value of 1 constantly for now so it seems like its unable to detect properly.