Author: @Joey Pereira (joey [at] pereira [dot] io)

Date: 2020-09-08

TODO

• [ ] Bundle up the AHK package more cleanly, remove bloat (device enumeration script).
• [ ] Add instructions for building ddcset in the repo.

By using DDC/CI (Display Data Channel / Command Interface), a protocol to control your display, and basic automation tools you can turn a USB switch into a software KVM that can control displays!

Here's what it looks like

https://s3-us-west-2.amazonaws.com/secure.notion-static.com/ee06916c-77ff-455f-bbcd-1d9f08f88277/VID_20200906_222243_(1).mp4

So what is this useful for? Lets take a look at the setup I have:

• There is a single monitor shared between two computers, a Macbook laptop, and a Windows desktop.
• A USB switch manually swaps the computer a keyboard and mouse are connected to.

My monitor is really annoying for switching input sources. It does not do the right thing when a source disconnects (eg: a device going to sleep) and it takes several menu navigations to change the source.

David Balatero had also just shared a writeup in my workplace's #protips channel for how to control display input sources to make a hot-key activated switcher, using DDC/CI. Amazing!

Create a quick monitor input switcher with Hammerspoon | David Balatero

When I shared this among friends, Jordan Verasamy had a great idea that found a problem (automated monitor switching) for a neat solution (DDC/CI + automation).