this post was submitted on 26 Feb 2024
17 points (100.0% liked)

Programming

17416 readers
52 users here now

Welcome to the main community in programming.dev! Feel free to post anything relating to programming here!

Cross posting is strongly encouraged in the instance. If you feel your post or another person's post makes sense in another community cross post into it.

Hope you enjoy the instance!

Rules

Rules

  • Follow the programming.dev instance rules
  • Keep content related to programming in some way
  • If you're posting long videos try to add in some form of tldr for those who don't want to watch videos

Wormhole

Follow the wormhole through a path of communities !webdev@programming.dev



founded 1 year ago
MODERATORS
 

Like let's say I have a few old HP alphanumeric LED displays that have a simple bit pattern protocol. I've gotten them working in Arduino a long time ago. If I can find some unused pins how can I bit bang them into a custom protocol from user space using pins that may be unrelated as far as I/O ports on a modern computer? Is it even possible without a kernel module? Am I stuck with using a serial channel like SPI/I2C/UART to talk to an external controller?

you are viewing a single comment's thread
view the rest of the comments
[–] computergeek125@lemmy.world 2 points 8 months ago

It being a laptop will almost undoubtedly make that endeavour more challenging. Off hand, I can't think of a single non -proprietary internal connector from a major vendor that doesn't already have a protocol established.

If there's spare I/O, it's most likely either not hooked up, was only used as a debug header, or fused off as a feature not available on that model. If it is indeed connected to something, you'd need to find documentation on that exact model of laptop since boards can sometimes vary even within the same series (such as whether a GPU is available). Chances are, whatever your find will need a specific vendor library that may or may not work on your version of the OS.

Unlike RPi and similar devices, you won't find many consumer x86 devices that leave GPIO available and documented.

Off-hand, I think almost every LCD display I've encountered on x86 is plugged in to either a serial (for character displays) or higher-level protocol (for more complex displays)