COMEDI_DIO_CONFIG(3)

💖 COMEDI_DIO_CONFIG 💖

okay bestie, pull up a seat, we're reading page 3 of the Comedi reference together and honestly? this one is a whole vibe. it's comedi_dio_config, and no cap, it's the little function that decides whether a digital pin is a listener or a yapper. let's go 🎀

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✨ NAME ✨

comedi_dio_config — change input/output properties of channel

so like… it flips a channel's whole personality between "i listen" and "i speak." iconic behavior tbh 👑

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🌈 SYNOPSIS 🌈

#include <comedilib.h>

int comedi_dio_config(comedi_t * device, unsigned int subdevice,
                      unsigned int channel, unsigned int direction);

four args, one int back. she's tidy, she's demure, she's got a comedi_t * 💅

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🦋 DESCRIPTION 🦋

okay so the function comedi_dio_config configures individual channels in a digital I/O subdevice to be either input or output, depending on the value of direction. literally that's the whole job and she does it flawlessly.

valid directions are COMEDI_INPUT or COMEDI_OUTPUT. that's the list. those two. don't get creative, bestie 🙈

⚠️ here's the tea though: depending on the characteristics of the hardware device, multiple channels might be grouped together in hardware when configuring the input/output direction. in that case, a single call to comedi_dio_config for any channel in the group will affect the entire group. so if you thought you were only touching one channel, surprise — you touched the whole friend group. not a bug, just how the silicon chose to organize itself 😭

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⭐ RETURN VALUE ⭐

if successful, 0 is returned, otherwise -1. classic. zero means slay, negative one means we're crying in the terminal 🌸

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👑 AUTHORS 👑

these are the legends who made it happen, show some respect:

• David Schleef <ds@schleef.org> — Author.
• Frank Mori Hess <fmhess@users.sourceforge.net> — Author.
• Herman Bruyninckx <Herman.Bruyninckx@mech.kuleuven.ac.be> — Author.
• Bernd Porr <tech@linux-usb-daq.co.uk> — Author.
• Ian Abbott <abbotti@mev.co.uk> — Author.
• Éric Piel <piel@delmic.com> — Author.

main character energy from every single one of them fr fr 🫶

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💜 COPYRIGHT 💜

Copyright © 1998-2003 David Schleef Copyright © 2001-2003, 2005, 2008 Frank Mori Hess Copyright © 2002-2003 Herman Bruyninckx Copyright © 2012 Bernd Porr Copyright © 2012 Ian Abbott Copyright © 2012, 2015 Éric Piel

This document is part of Comedilib. In the context of this document, the term "source code" as defined by the license is interpreted as the XML source.

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, version 2.1 of the License.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

🫶 real talk though: WITHOUT ANY WARRANTY means literally no promises, so please don't come for anyone if your USB DAQ does something feral. the license said what it said 💀

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and that's the page, bestie 💖 this little corner of the Comedi manual was served up on 03/20/2026 — so when you're out there flipping pins between COMEDI_INPUT and COMEDI_OUTPUT, remember the group-chat: one call, whole group affected. stay slay, stay grounded, and go configure something gorgeous ✨🎀🦋