HDMI out not working

[Zarhan]

I finally tested the USB-C to HDMI adapter from Planet. Cannot get it to work.

The screen (LG 55" TV) shows that the connector is connected (but it shows this regardless of whether the adapter is actually connected on the USB port side). However, there doesn't seem to be any signal.

I checked with termux/su and "lsusb" clearly shows that Cosmo does detect at least *something* in the USB port (two devices, 1d6b:0002 and 1d6b:0003). So I guess the adapter should work...?

The only selection related to HDMI is "open HDMI" in settings, and turning it on or off doesn't have any effect.

Is there some procedure I'm missing? Has *anyone* gotten their HDMI output to work?

[Zarhan]

Never mind, I guess(?)

I tried with my desktop PC's monitor (A 32" Samsung). Took a bit of work since it's mounted in a rather nonaccessible fashion (and uses Displayport for my PC so I didn't have a cable end hanging). Anyway, I attached the cable/adapter to it and....HDMI did not work.

Tried again, secured all connectors.

Turned off Wifi just in case casting would interfere with HDMI out.

Finally, flipped the USB-C connector to other polarity. Lo and behold, immediately started working.

1920x1080, 60 Hz, so essentially nothing special.

Flipped the USB-C connector *again* and...it stayed working. No matter how many times I unplugged the adapter and put it back in. Turned of Wifi. It still worked.

Afterwards, I tried all the same combinations with the LG TV again. No-go. So there's I guess *some* compatibility issue with, well, some displays.

So...essentially, I've confirmed that the adapter does work, at least with a single display, but I really wish I knew what are the requirements for the HDMI to actually work. Is there some bad soldering on the connector, or what exactly is going on?

[spook]

You obviously did not perform the recommended goat sacrifice . But seriously, I've found it very hit and miss and I can't determine why it will work on some instances and not others. In the end, I bought a DisplayLink HDMI adaptor. They're not cheap, but they work 100% of the time. Essentially they have a little display chip in them. Again - nothing spectacular. Just 1080p, but if reliability is what you need for video out ,  are your only option.

[gymbo]

You obviously did not perform the recommended goat sacrifice .

But wouldn't needing to bring a goat along kind of defeat the purpose of having a small device with keyboard??

Of course you could have the goat carry your device until you needed the HDMI out, but I do believe you would be quite limited in you traves/movements with a gout in tow. And I do believe quite a few people would object to you sacrificing the goat as well. Not to mention the cleanup needed afterwards...

(But yes, there seems to be some "magic" involved in getting some things working, at least on the Gemini, haven't even gotten my Cosmo yet       )

[mmbika]

In the end, I bought a DisplayLink HDMI adaptor. They're not cheap, but they work 100% of the time. Essentially they have a little display chip in them. Again - nothing spectacular. Just 1080p, but if reliability is what you need for video out ,  are your only option.

Could you please care to quote which make and model? Mr eBay shows all with USB A connector and not USB C

[Daniel W]

One thing, that may cause issues for some displays, is the slightly odd resolution. Regular Full HD is 1920x1080, but the Planet Computers devices outputs the same resolution as their internal displays, which is 2160x1080. The three TV sets I've tried with, has worked, so I think it's more common that it works than that it doesn't.

[Zarhan]

One thing, that may cause issues for some displays, is the slightly odd resolution. Regular Full HD is 1920x1080, but the Planet Computers devices outputs the same resolution as their internal displays, which is 2160x1080. The three TV sets I've tried with, has worked, so I think it's more common that it works than that it doesn't.

Then the monitor I use with my PC (2560x1440 native resolution) must have lied (Samsung 32" something). It claimed that Cosmo was outputting at 1920x1080.

I guess it might have just be a problem with the OSD of the monitor. But this would definitely explain why it didn't work with a regular TV. I wonder if there's any way to set the resolution...

[MonkeyControl]

You obviously did not perform the recommended goat sacrifice .

control-goat-delete

[spook]

In the end, I bought a DisplayLink HDMI adaptor. They're not cheap, but they work 100% of the time. Essentially they have a little display chip in them. Again - nothing spectacular. Just 1080p, but if reliability is what you need for video out ,  are your only option.

Could you please care to quote which make and model? Mr eBay shows all with USB A connector and not USB C

Mine is a USB-3 type A conector. I have to use a little USB-A to USB-C adaptor.

[Daniel W]

Then the monitor I use with my PC (2560x1440 native resolution) must have lied (Samsung 32" something). It claimed that Cosmo was outputting at 1920x1080. I guess it might have just be a problem with the OSD of the monitor. But this would definitely explain why it didn't work with a regular TV. I wonder if there's any way to set the resolution...

Some screens seems to mostly just check the image height and then presume the aspect ratio to be either 4:3 or 16:9. Just to be sure, I hooked the Cosmo up to a Grundig FHD TV, and it just said 1080p@60Hz, but the black bars at the top and bottom clearly showed that the image from the Cosmo is wider than the 16:9 aspect ratio of the TV (and thus scaled to fit) and since the internal screen of the Cosmo is 18:9, that makes sense. AFAIK there's no way (in Android, anyway) to change the resolution or frame rate.

Since the TV has a Netgear PTV3000 Miracast reciever (with FW 2.4.53) attached, I tried Miracast as well, and got the same resolution and frame rate. I haven't measured the audio or video lag yet, but from the Gemini, I seem to recall it was around 150ms for the HDMI adapter and more tah double that for Miracast (and both had a different lag for video and audio, causing lipsync issues)

[JamesGem]

Does anyone know if these DisplayPort devices work under any of the Linux distributions run on these devices?  I bought my device to do a bit of tinkering with Linux and programming on the go. It would be nice to occasionally be able to hook the device up to a larger screen. When I asked PC about their own HDMI converter, they confirmed what had been discussed in the Gemini forums about it only working under Android.

[mmbika]

Does anyone know if these DisplayPort devices work under any of the Linux distributions run on these devices?  I bought my device to do a bit of tinkering with Linux and programming on the go. It would be nice to occasionally be able to hook the device up to a larger screen. When I asked PC about their own HDMI converter, they confirmed what had been discussed in the Gemini forums about it only working under Android.

You know they made a very thought out super-duper intelligent product for equally super intelligent human beings like us who fail to understand simple thing that android is a super desktop operating system copmared to primitive os ike linuxes etc. and everything looks super cool on a external monitor on android, linux is made for alien who can do desktop comuting on a 7" screen with xray eyes ! they are even making new device versions with even better desktop grade android.

[Varti]

You know they made a very thought out super-duper intelligent product for equally super intelligent human beings like us who fail to understand simple thing that android is a super desktop operating system copmared to primitive os ike linuxes etc. and everything looks super cool on a external monitor on android, linux is made for alien who can do desktop comuting on a 7" screen with xray eyes ! they are even making new device versions with even better desktop grade android.

Yes, I agree that it is unfortunate that the HDMI cable doesn't work under Linux, but I think that the reason for not fixing this issue is a different one. A more probable reason is that the MTK driver for the cable is closed source and that Mediatek won't release the sources to Planet, and maybe to anyone else. So a driver might be developed only by reverse engineering the existing one, something that Planet might be not allowed to do.

Varti

[mmbika]

You know they made a very thought out super-duper intelligent product for equally super intelligent human beings like us who fail to understand simple thing that android is a super desktop operating system copmared to primitive os ike linuxes etc. and everything looks super cool on a external monitor on android, linux is made for alien who can do desktop comuting on a 7" screen with xray eyes ! they are even making new device versions with even better desktop grade android.

Yes, I agree that it is unfortunate that the HDMI cable doesn't work under Linux, but I think that the reason for not fixing this issue is a different one. A more probable reason is that the MTK driver for the cable is closed source and that Mediatek won't release the sources to Planet, and maybe to anyone else. So a driver might be developed only by reverse engineering the existing one, something that Planet might be not allowed to do.

Varti

only regret I have, rather planet should have, is that didn't planet thought about all those probabale issues beforehand and shouldn't have they fixed them out before going out and misleading people about and raising false expectations? who wants a 7" desktop to kill their eyes? why and what is making such half-baked products to flood market, ios being a prime examplle of it. why not be honest and tell people that nothing will work out of the box on linux or nothing will work properly ever on linux? I bought it primarily for desktop repllacement with a simple thought that I will be able to connect it with an external monitor and have a full desktop os. how many of us haven't had that thought?

Only other thing I can think about as a work around would be wireless display. I have used Microsoft WiDi Adapter with HDMI out with Cosmo and it works, a bit slugish. If Linux can support WiDi than may be we have an option for time being. I haven't installed and do not plan until it is soild for daily use out of box, can't and don't want to waste a lot of time fixing Linux as well as spoiling working Android and take a chance of bricking the whole device for no benefit in the end. Have had enough pain with mucking around and playing many such half baked concepts so very honestly I stay away from them allm even normal updates scare me having my Windows screved to BSOD a million times after updates that I completely disabale that, I had better live with few malware than living with crackpot quacks who claim to fix it and in turn get it worse.

[SwordfishII]

You know they made a very thought out super-duper intelligent product for equally super intelligent human beings like us who fail to understand simple thing that android is a super desktop operating system copmared to primitive os ike linuxes etc. and everything looks super cool on a external monitor on android, linux is made for alien who can do desktop comuting on a 7" screen with xray eyes ! they are even making new device versions with even better desktop grade android.

Yes, I agree that it is unfortunate that the HDMI cable doesn't work under Linux, but I think that the reason for not fixing this issue is a different one. A more probable reason is that the MTK driver for the cable is closed source and that Mediatek won't release the sources to Planet, and maybe to anyone else. So a driver might be developed only by reverse engineering the existing one, something that Planet might be not allowed to do.

Varti

Varti, the cellular stack, bt and wifi and hardware acceleration are all closed source android.

Linux utilizes libhybris as a wrapper for the android blobs, so it is strange that hdmi was not included