Connect with us

micro I/o lines

Discussion in 'General Electronics Discussion' started by Rajinder, Dec 16, 2016.

Scroll to continue with content
  1. Rajinder


    Jan 30, 2016
    Hi all,
    I need to understand micro I/o lines for a PIC 18F.
    If I put a 10k pull up on a pin, and configure the pin as a input. It will read high. But if the same pin is set to an output, what happens? Also can I drive this low even though it has a pull up, by this I mean using the internal FET or open collector transistor inside the micro?
    Best regards
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    Jan 21, 2010
    Unless something else pulls it (harder) to ground.

    The output takes the state you set it unless the pull up resistor has such a low value that the microcontroller can't pull it low. in addition, when you set the output to a low state current will flow through the resistor.

    Yes. If the output is open collector then this is the only way to get a high level on the output.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day