Is MHL desireable for USBC to HDMI?

kristoffo · #1 05-10-2021, 08:52 PM

Hi folks in the only forum that gets instant and reliable answers to all questions about "life, the universe and everything"....
I just got my first smartphone....
I call them stupidphones cause they obvioiusly are making the world stupid....
Galaxy A32 5G with T-Mobile....
Chosen mainly because it has USBC....
Which a few years ago I read enables us to mirror a phone to a TV via HDMI....
And I was once stuck in a hospital for several weeks....
And Chromecast did not work because it required an online log-in which the hospital's wifi firewall would not allow....
But no problem projecting Netflix to any TV screen with an HDMI cable....
And so when i heard about this new USBC that connects to HDMI...
I thought cool....
If I ever get what I call a "stupidphone"....
And am stuck in a hotel room or waiting room or hospital without my laptop....
And if only the stupidphone has USBC....
Maybe I can edit a blog or watch Netflix without developing a permanent squint....
At first a USBC phone was $400.... Then $195.... And now free with trade-in....
But here's the problem....
I want either a hub with several types of outlets
OR a 10-12 ft cable....
But...

Most USBC-to-HDMI listings specify they are for Apple devices.... Does that matter?
Those 2-3 that mention the Galaxy A32 (with or without 5g) are simple cables--at most 6 ft--no good for anything...
Many reviews complained of multi-use hubs being cheap trash that does not work as claimed.... So i decided to surf....
Google results showed one page about A32-to-HDMI and said JUST MAKE SURE IT IS MHL COMPATIBLE... "Go to Amazon and you will find thousants...." https://provscons.com/pros-and-cons-...galaxy-a32-5g/
But.... Of Amazon adapters that specifically list the A32... NONE mentions MHL... (Including one that was recommended by a link in the above article!)
And... the 2-3 nice-looking hubs with USBC-to-MHL have few and mostly negative user ratings...
Other MHL hubs seem NOT for USBC but regular USB.... Often with reviewers saying "it does not work..."
Some MHL adapters have regular USB plugs plus little adapter-ends that make them fit USBC.... Can I even rely on that working?

And so the following questions arise in my mind....

IF I have MHL then is USBC necessary--or can ordinary USB connect to HDMI IF both gadgets are MHL compatible?
IF I have USBC then is MHL necessary?.... Or is USBC actually a sort of mini-HDMI that can work directly with any HDMI? (Just like my laptop does. And as was my impression when I first read about USBC.)....
And so... for a device that has USBC.... might an MHL adapter actually REDUCE compatiblity to those not-all-TVs with MHL compatibility? I.e. maybe better NOT get MHL if I have a USBC??
And... does it matter whether a USBC-to-HDMI adapter is advertised primarily for Apple products vs. Androids?
Is it even possible to get a reliable multi-use hub including usbc-to-hdmi? Or--so far as HDMI mirroring is concerned--is it really best to carry around a 10-12 ft cable with HDMI and USBC plugs hard-wired onto the ends? Some reviewers of some of those hubs (maybe all of those hubs) complain about "flickering" due to "lose fitting" hub outlets.
Current status::: I came across one negative reviewer who recommended the following different hub which he said, "costs a little more but finally found one that gives nice tight connections...." Also has free returns with Amazon Prime. https://smile.amazon.com/gp/product/B07M6R3CPB
And so I gave up trying to decide whether or not to get MHL.... Whether or not the adapter seems to be for Galaxy or Android or Apple.... And I ordered that "tight fitting not-so-cheap non-MHL" hub...
Anyone please let me know whether you think the hub I ordered will work.... And whether or not my vague ideas about USBC and MHL are partly correct.... Or not? And anything else I should know? Thank you anyone.

JustinTArthur · #2 09-08-2021, 12:30 PM

All good questions. I'm unable to find any real specs from Samsung that suggest the A32 supports any known standard for connecting a USB-C device to a display. I'll get to the standards in a minute, but my guess is that it just won't happen on the A32 given it's an entry-level device.

If you're unable to get Chromecast to work, you might be lucky to find the TV supports Miracast for mirroring on its own. The Samsung Smart View app will power this mirroring capability for the A32. Some TVs will require you to go to a mirroring TV app or settings pane in order for the TV to accept the mirroring request from Samsung Smart View.

On to your questions about MHL. MHL is a strange standard. It was very popular on previous-gen USB smartphones–ones that have a Micro-USB Type B (USB Micro-B) port. This allowed an HDMI-like signal to go from the phone to an HDTV by one of two means:

MHL Passive HDMI adapter, which transports MHL's HDMI-like signal directly to a TV with via an HDMI physical connector. The TV would have to explicitly have MHL support.
An active MHL HDMI adapter which would convert MHL's HDMI-like signal to a real HDMI signal over an HDMI physical connector. These adapters often required extra power, such as from another USB source device. This is why some of the adapters you see have that extra USB port.

This MHL tech is theoretically possible over USB-C. The company that sells the MHL standard and testing pushed successfully to get a way to support MHL in the official USB-C standard, however it's important to note that almost no companies adopted this mode of USB-C operation despite how hard MHL, LLC advertises the technology. This compatibility is called "MHL Alternate Mode for USB 3.1" or "MHL Alternate Mode for USB Type-C". I have yet to see a single adapter for such a stack in the wild.

So how do so many USB-C devices support adapting to HDMI? They do it through a competing standard called DisplayPort Alternate Mode on USB-C. This tech actually is getting adopted and is what most display adapters for USB-C devices are using. The standard is more sensible for most tech companies to use because most of them are members of the company that makes, sells, and tests the DisplayPort standard: VESA. Another reason why it makes sense for these companies to adopt DisplayPort Alternate Mode on USB-C is that you effectively get HDMI interoperability for free. DisplayPort and HDMI are two different things, but the technology required to get a DisplayPort source talking to an HDMI display has already been around for ages. DisplayPort Alternate Mode on USB-C adapters for HDMI do require a bit of power to actively convert from the DisplayPort signal to an HDMI signal.

To make things extra confusing there is now (as of 2016) a standard to natively support HDMI in a USB-C port called HDMI Alternate Mode for USB Type-C. There are a couple of chips out there for someone wanting to build a smartphone that supports it, but I haven't seen a device like this yet. This may become popular in the future. Connecting to an HDMI display this way would mean having lower power requirement for the adapter (which can be passive) and could support some HDMI goodies like remote control. It would mean that all the USB-C to HDMI adapters out there would have to start being explicit about which USB-C alt mode standard they are for, which would have been nice to have in the first place. It would also mean extra royalties cost for companies that want devices that support both DP and HDMI alt modes.

kristoffo · #3 09-08-2021, 06:32 PM

Wow thank you very much JustinTArthur.

Especially saying my questions were good. Otherwise I could not be sure.
And like I said--this DigtalFAQ forum is the greatest.
I gave up waiting for a reply--and now here it is--above and beyond.
Also reassuring that I was not totally stupid for assuming any USBC should convert easily to any HDMI.
And I hope you will excuse me for not perhaps totally understanding you...
But I think this is the general gist of what you are saying...

In this post "1984" and post "2001" and "Brave New World"...
The more we standardize the less we standaradize...
The more we humanize and intuitive-ize the less..
The more we simplify the more we complicate...
And so therefore... there are converters from USB to HDMI... But USBC to HDMI was supposed to be so much more simple and direct... but maybe is not at all.
So my best chance for my USBC to do what was supposedly a raison d'etre for USBC... is to make darn sure my specific model of "stupid phone" is listed by the USBC converter product... and if possible that the conversion method is supported at the other end...
And if I want to carry something around that might usually cast from phone to hotel or hospital TV... forget USBC and its alleged r'aison d'etre... just get chromecast or something like that.
Or just be sure to bring my laptop. Which always works fine with any TV and with any cable that has a standard HDMI plug at both ends.
And perhaps...... All I have got by insisting on USBC in my new phone...... is primarily the need to carry around twice as many charging and connecting cables.... one set for my USBC and another set for everything else which still uses USB or mini-USB.
And hmmmmmmmmmmm...... perhaps when I upload photos or whatever from stupid phone to laptop or desktop........ It might not be so easy from USBC as it might have been from mini-USB to medium-USB.