PIC interface with...?

[syntium87]

hi guys...

i want to ask about this matters..i have a 12V switch..and i would like to interface it to a pin from any port of PIC16f877a..
inside the switch have the 12V led..so the switch is a (push button + 12V led)..i dont know why in the catalog i buy from it said switch ..

anyway..whenever the PIC gives an output it means that 5V output right?so how i'm going to connect this switch so that it can be turn on the led (output) and i can press the switch(to give input) to the pic...can it be done on a single PIC pin??
what are the device i need to connect between the PIC and the switch??

[Brian Griffin]

You need isolation between the port pins and the high voltage device. Failing to do so may destroy your microcontroller.

Read up about relays and isolations in the 'net. There is plenty of information about that online.

[robosang]

Not really sure what is the switch look like. But if the LED is mechanically switch on, you can have a voltage divider to read 5V from 12V.

[shahrul]

I don't get what the device? Is that a switch with LED indicator?
You may test how much current flow to light-up the LED, I think it's not necessary 12V.

[syntium87]

the switch / push button i want to use is the illuminated push button which used in factory or industrial area..the one with red and green light (on and off machine)..inside the push button is... [push button + led 12V + contact block(like a relay) ]...

this illuminated push button have a maintained function (which is the when the button is pressed it maintain...and press again to release the button)..

how to interface the pic with this illuminated push button..?help me plzz...

[yonghui]

pls check the circuit functionality and the value of the resistor according to the current requirement

[syntium87]

if im using optocoupler..how to interface it with the PIC...?n can the cct have the feedback signal to the PIC??
still not really know how to program the optocoupler...

help....

[robosang]

We do not know which switch you are talking about, if you look at the reply from other, it is assumption you are using this and that switch, if you really want us to help you, capture a picture or datasheet, show it to us.

[syntium87]

sory everyone..this is the switch that im talking about..
link --- > http://www.apem.co.uk/pdf/UKS%20PDFs%202009/6-12.pdf

i really dont know how to program n interface it with mcu

[ober]

Assuming you are using A01 series. The datasheet show pin 1 is connected to pin 3 by default, when the button is press pin 1 is connected to pin 2.

Just take pin 1 and pin 2 as your switch terminal, like normal small push button. Look at the the sample schematic from Cytron DIY project. There are tons of sample using push button. As for the LED, you will need to test for the correct terminal. Try to connect 12V (=) from power supply to pin 1, and the gnd to pin 3. Press the button and look at the LED, if is is not illuminated, try reversing the terminal, + to pin 3, Gnd to pin 1.

Since it has 2 poles, the LED should have separated connection with Push button you are going to you. You will need to get it right first.