From this picture (electrical drawing) it looks clearly like an NO-NPN sensor and yet on every page where this product is on sale, it said that "Output type: Three-wire PNP positive logic output"
Does anyone here have experience with it or with any PNP sensors with arduino? And if you have used PNP sensors, can you please tell what I have to do to get it working because everywhere I read that NPN sensors are preferable and with PNP sensors you need and opto-isolator.
On this page
you can see a better image of the sensor I'm refering to (just click the picture and take a look at the 2nd and 3rd pictures.
Usually those sensors are sold with a selection of output types. You certainly cannot trust a picture, and must make sure that you are ordering and getting what you want.
It is not required to use an optoisolator with a PNP output -- you can use a voltage divider to reduce the output voltage to a safe level for the Arduino input. With a PNP output there is a slightly higher risk of damage to the Arduino if sensor wire breaks. If that worries you, it is not difficult to use an optoisolator.
So I have an 6-36v inductive proximity sensor (PNP NO) that i would like to use with arduino. The application i'm hoping to make is to have a robot arm bring metallic and non-metallic objects to the sensor and then separate the objects in their own stacks.
In this video it is said that "there is a high probability that you are going to burn the arduino with a PNP sensor". He also says that you should use an opto-isolator when connecting PNP sensor to arduino.
Is this true? Does anyone here have experience with connecting PNP-sensors with arduino? If you do, could you tell me how to safely connect one to arduino.
jremington:
Usually those sensors are sold with a selection of output types. You certainly cannot trust a picture, and must make sure that you are ordering and getting what you want.
It is not required to use an optoisolator with a PNP output -- you can use a voltage divider to reduce the output voltage to a safe level for the Arduino input. With a PNP output there is a slightly higher risk of damage to the Arduino if sensor wire breaks. If that worries you, it is not difficult to use an optoisolator.
Thanks jremington. I already got another proximity sensor (PNP) and made a topic concerning their use with arduino. Do you have an example of using voltage divider with arduino or with proximity sensors?
http://forum.arduino.cc/index.php?topic=366766.0
"there is a high probability that you are going to burn the arduino with a PNP sensor"
True if you know little about electronics and don't bother to research how to make the connection.
The answer depends to some extent on the sensor power supply. What supply voltage will you be using?
Why start another thread? It just leads to confusion.
@realhumanbean, do not cross-post. Threads merged.
