Using Pic16F84 to connect pins together

Discussion in 'General Electronics Chat' started by xpn, Mar 1, 2011.

  1. xpn

    Thread Starter New Member

    Aug 25, 2009
    Hi All,

    I currently have a project where I need to connect 2 pins on an IC together. I am using my PIC16F84 microcontroller.

    I know that I can use a transistor to achieve this, but was wondering if there was any way to achieve the same result with just a PIC controller?

    If not, and I have to go down the transistor route, is there anything that I should watch out for, as the PIC is on a different power source to the IC that I need to interconnect pins for?

    Thanks (and I hope that made some form of sense :D).

  2. SgtWookie


    Jul 17, 2007
    If the PIC is on a different power source, then you will need to use a photocoupler/optoisolator so that the voltage difference doesn't matter that much. Examples of photocouplers/optoisolators are the 4N25, 4N33, etc. There is an IR emitter on the input side, and a phototransistor on the output side. You can power the IR emitter from a PIC pin via a current limiting resistor. The phototransistor generally is not able to source or sink much current; perhaps a few milliamperes.

    You're not saying anything about what this other IC is that you need to connect the pins together, or which pins. Depending on how good the connection needs to be, you might be able to simply use the phototransistor output to connect them (if a ground is involved), or you might need to do something like switch a relay.

    Without more information, it's going to be difficult to make a decent recommendation.
  3. xpn

    Thread Starter New Member

    Aug 25, 2009

    To be honest, the IC is unknown. I have torn apart a remote control with an unlabeled IC that does the controlling. I thought the push buttons would just be connecting a IC pin to GND or +9v, but it turns out they the push buttons just connect 2 pins of the IC together.