The DisplayPort altmode is semi-proprietary, but it can absolutely be picked apart if we try. Last time, we found a cool appnote describing the DisplayPort altmode in detail, switched the FUSB302 into packet sniffing mode and got packet captures, learned about PD VDMs (vendor-defined messages), and successfully replayed the captured messages to switch a USB-C port into the DisplayPort altmode. Today, we will go through the seven messages that summon the DisplayPort altmode, implement them, and tie them all into a library – then, figure out the hardware we need to have DisplayPort work in the wild.
USB-C might have its problems, but it’s also incredibly cool and versatile.
USB-C might have a reputation of having problems, but in fact I found it awesome, especially in the recent times.
The main issue most people have can be traced to a low quality cable, or a cheap USB hub. Moving to Thunderbolt cables (yes they are more expensive) and medium to higher quality docking stations change the equation a lot.
Being able to carry laptop power, keyboard, mouse, camera, Ethernet, audio, and of course DisplayPort / HDMI signals over a single cable is something I don’t want to go back from.
sukru,
My dad needed to use HDMI output and that’s when I discovered that google intentionally disabled the feature on newer android phones.
https://www.trustedreviews.com/news/google-disabled-pixel-4-usb-c-video-output-source-code-3951776
Unfortunately HDMI won’t work on new models incorporating google’s change. My older oneplus phone doesn’t have google’s patch and supports HDM, My wife needed this functionality on her phone for meetings but discovered it was blocked on her new phone. I absolutely hate when corporations go out of their way to make products worse. In google’s case it was very likely to force users to buy chromecast.
Alfman,
I had no idea they disabled a perfectly nice feature. That is not good at all.
But Google being Google, this explanation is probably more likely
They have become extremely risk averse over time
sukru,
Well, I’ve got two comments for this:
1) My own first hand experience is that HDMI worked fine up until it was disabled. My Dad, who isn’t a tech savvy person, is significantly more disappointed that HDMI got disabled. Believe me he was really annoyed that his new expensive phone wasn’t capable of it when my older phone was. The truth is we’d much rather have it than not and if anything people who need to use HDMI might end up switching to an apple device that works, which is ultimately what my dad did to connect to the TV.
2) To the extent that google might have unintentionally introduced an HDMI related bug at some point, I understand that can happen but then isn’t the appropriate course of action to fix it? It just seems incredulous to me that a company of google’s stature was unable to fix it and decided that instead that their best course of action was to permanently disable HDMI support. Meanwhile other android vendors still had HDMI working.
With these things considered, IMHO google did it on purpose to help sell chromecast.
Alfman,
This is probably very on brand for Google.
There is an overall corporate prioritization issue that has been known, but will take a lot of time to fix.
That is also the reason of abandoning so many seemingly successful projects as well.
Hopefully it will get better. Otherwise I can’t see Google being as successful in the future.
What’s really pathetic is that I could connect my Nokia 5800 ‘XpressMusic back in 2009 without issues but with Android it has been a struggle.
Samsung does it right.
Then even have a mode called “DeX” that transforms the UI into a semi-desktop one: windowed user interface, start menus, etc. (However it requires their own dock for higher resolutions).
Actually Android has introduced such a generic mode in recent versions. But it seems to be optional and vendor specific. (Specifically Google does not seem to support in on their own hardware).