What does HackerNews think of ddcctl?
DDC monitor controls (brightness) for Mac OSX command line
That's when I developed the first version of Lunar (https://lunar.fyi) to adapt brightness automatically throughout the day based on the sun position in the sky. (reading the light sensor was not possible at the time)
That combined with Night Shift (macOS native version of f.lux) fixed most of my problems.
I also tried blue light filter glasses but the only effect they had was removing more money from my savings. I feel like this is just modern day snake oil for computer workers.
In the end, what fixed all of my problems was a LASIK [1] operation (well actually PRK because I had only a small abberation). I still recommend this to all my friends and relatives who are always complaining about their vision. It did change my life.
I still cringe when someone turns on an overhead lightbulb though, I never use those in my home. Turns out this wasn't my astigmatism, it's just that most LED bulbs are simply too bright single point lights.
I fit my home with TRADfri warm light lamps hidden behind sofa/door/desk [2], WLED-powered [3] LED strips and simple string lights (like you can see in the front page video on https://lowtechguys.com/volum/)
[0] https://github.com/kfix/ddcctl
[1] https://en.wikipedia.org/wiki/LASIK
[2] https://www.ikea.com/gb/en/p/tradfri-remote-control-kit-smar...
It started in 2017 when I shared the first free and open source version of Lunar (https://lunar.fyi/), an app for controlling monitors.
At that time, there was only a command line for doing this stuff (https://github.com/kfix/ddcctl) and I wanted a more visual way of changing the brightness. So I learned Swift, learned how to bridge the ddcctl C code and call it from Swift, then made a rough interface and published it: https://www.producthunt.com/products/lunar#lunar-5
It turned out people did have a need for this and asked if they could donate. I set up a Buy me a Coffee page and in 4 years collected about $5k in donations. That's a lot of money for a Romanian.
When Apple Silicon appeared, Lunar didn't work anymore because the whole hardware arrangement and drivers were different, and there was no documentation on how to send I²C data. I took the plunge and quit my stressful job, bought an M1 MacBook and reverse engineered the I²C communication: https://alinpanaitiu.com/blog/journey-to-ddc-on-m1-macs/
Then published Lunar 4 as a Free version with a Pro paid upgrade. I was reluctant with this, didn't think anyone would buy it, but to this day I'm able to be unemployed and put my ideas into practice because of it.
So computer monitors have support for a communication protocol called Display Data Channel which is normally used by the host (Mac, PC) to get info about supported resolutions, frame rates, signal timing etc.
On top of that, a command interface has been created called MCCS or Monitor Control Command Set [1] which allows changing brightness, volume, input and a ton of other aspects of the monitor, by sending specific bytes through the cable. That cable can be HDMI, DisplayPort, Thunderbolt, VGA, DVI. It doesn’t matter, as long as it has dedicated wires to carry the I2C signal.
I2C is the 2-wire communication protocol used by DDC, and it basically defines things like “a pulse of 5V (volts) of x milliseconds followed by 0V of y milliseconds means the 0 bit. The 1 bit is represented by a pulse of 5V of 2x milliseconds”. It’s a bit more complex than that, also defining TCP-like features with data frames and ACK packets, but you get the idea. It’s something that both devices agree on so that they can send raw bytes using 5 volt pulses.
I’ve created Lunar as an adaptive brightness app for macOS after finding out about a little CLI called ddcctl: https://github.com/kfix/ddcctl
That’s where I learned how DDC packets look like, where to place the payload (brightness value between 0 and 100, input ID, etc) and how to write that to the monitor using the macOS I2C APIs.
When Apple Silicon came out, none of that was possible anymore so I had to go looking around kernel assembly and private macOS frameworks for “the Apple Silicon way” of writing data through I2C.
If you’re also curious how I learned that, it’s a very cool domain called “reverse engineering” and I learned it while working as a Malware Researcher at Bitdefender. A bit hard to get started, but so many gems to discover once you know how to open binaries in IDA/Hopper and look around their disassembled code.
I'm forever grateful to the ddcctl [1] project which enabled all these monitor control solutions.
I have to reverse engineer a lot of macOS internals and some hardware too to make some features possible. I don’t want to keep that for myself. This XDR thing makes an exception because it required a lot more RE work than I expected I’d like to get some publicity for it before open-sourcing and writing it up.
I don’t think I can take advantage of the open source community here. The OSS community has largely chosen MonitorControl since it is fully open source, free and accepts contributions.
I couldn’t have started Lunar without the open source ddcctl [0] project, and I want to give back as much as I can without jeopardizing sales and having to go back to a 9-to-5 job.
- the USB-C charging was terrible because if you turn off the monitor it stops charging the laptop. I believe the same happens when the monitor sleeps. There is also this weird connectivity issue that happens if the mac with USB-C goes to sleep and the monitor is in use with another port. It keeps detecting/undetecting the USB-C port. I think it basically comes down to a lack of consistent power connection from the monitor to USB-C port. I knew about this problem and I just make sure my mac has a power brick plugged in.
- the 2nd problem was that their isn't any Dell software for mac which means that all settings and switching is done through the buttons. Luckily, someone hacked this together.
https://github.com/kfix/ddcctl
Overall, the monitor is absolutely fantastic and I would buy it again. I spent at least 40 hours researching monitors and looking for a high resolution (4kish), 32" or larger, IPS monitor. Everything else was either super expensive, out of stock/no longer made or had major problems.
That was on HN earlier this year. Basically it's software that you run and set up to detect when certain peripherals connect/disconnect and have it switch the input on the monitor automatically. I've been using it and, while not always perfect, it actually works pretty well, especially considering the price.
If you don't always want the monitor to switch inputs (sometimes I just want to quickly switch my keyboard/mouse to my laptop to do something but don't want to switch monitor inputs) you can also just set up shortcuts or scripts (I created an Alfred workflow, for example) and use something like https://github.com/kfix/ddcctl to switch monitor inputs.
alias verydull="~/Software/ddcctl/ddcctl -d 1 -b 3 -c 15"
alias dull="~/Software/ddcctl/ddcctl -d 1 -b 6 -c 35"
alias decent="~/Software/ddcctl/ddcctl -d 1 -b 10 -c 40"
alias medium="~/Software/ddcctl/ddcctl -d 1 -b 25 -c 50"
alias bright="~/Software/ddcctl/ddcctl -d 1 -b 30 -c 50"
alias morebright="~/Software/ddcctl/ddcctl -d 1 -b 35 -c 60"
alias superbright="~/Software/ddcctl/ddcctl -d 1 -b 100 -c 80"I just tried ddcctl ( https://github.com/kfix/ddcctl ) - and it worked perfectly over HDMI through a HDMI switch. I didn't even know what to look for - so this comment was a lot of help.
I have a script hacked together to fetch the internal display's brightness once a minute and apply it, with a scaling factor, to the external, so that they're both effectively controlled by the laptop's ambient light sensor. It's really nice for working in a room with lots of windows.
A more batteries-included alternative, which appears to also provide brightness sync, is Lunar (https://lunar.fyi/). I haven't had a chance to try it, but the Github repo makes it look pretty solid.
There are probably more fancy things out there that integrate via .prefpane or something, but works good enough for me.
About that, I have had some luck with https://github.com/kfix/ddcctl to adjust an external monitor brightness and 'brew brightness' to read the current brightness of my MBP.
I set that up in a cron job and that works well enough (although with a delay) with the brightness button of the MBP. The delay is less important to me as I use it essentially to sync the monitor brightness to the MBP autobrigthness.