Thanks to the worldwide proliferation of smartphones, tiny high-resolution displays are common and cheap. Interfacing these displays with anything besides a phone has been a problem. [twl] has a board that does just that, converting HDMI to something these displays can understand, and providing a framebuffer so these displays can be written to through small microcontrollers.
[twl] is using a rather large FPGA to handle all the conversion from HDMI to the DSI the display understands. He’s using an Xilinx Spartan-6-SLX9, one of the most hobbyist friendly devices that is able to be hand soldered. Also on the board is a little bit of SDRAM for a framebuffer, HDMI input, and a power supply for the LCD and its backlight.
On the things [twl] has in his ‘to-do’ list, porting Doom to run on a cellphone display is obviously right at the top. He also wants to test the drawing commands for the Arduino side of his board, allowing any board with the suffix ~’ino to paint graphics and text on small, cheap, high-resolution displays. That’s a capability that just doesn’t exist with products twice [twl]’s projected BOM, and we can’t wait to see what he comes up with.
You can check out the demo video of [twl]’s board displaying the output of a Raspberry Pi below. If you look very closely, you’ll notice the boot/default screen for the display adapter is the Hackaday Jolly Wrencher.
74 thoughts on “Using Cell Phone Screens With Any HDMI Interface”
Dual 4K Oculus rift, here we come :D
What 4k phone LCD do you know of?
LG g3 for one
It shoots 4K video. But the display is 2560x1440p
source: I own one
I’ve been told it’s almost not possible to go over FHD via hdmi on those mobile screens as of yet
r3: I find that very hard to believe. We know for a fact that there are 1440p smartphone displays out on the market already (in the LG G3 and Samsung Galaxy Note 4). We also know that there are existing HDMI receiver chips that can handle 2k and, possibly, even 4k (such as the Analog Semiconductors ADV7619, to say nothing of the other HDMI receivers that must exist in order for all the other, larger, 2k & 4k monitors out on the market).
Now, it may be possible that this particular project can’t handle 1440p if the FPGA he used just can’t handle the bandwidth and/or processing power, but that wouldn’t be a universal issue in regards to all mobile screens over FHD (1080p). Is that what you were referring to?
@Colecoman – – – i’m not sayin it’s technically impossible .. all i’m sayin that if i wanted to get some of dem boards from china ( they got all sorts of stuff ) ; however, I’ve asked specifically for this solution and response was … maybe in 6 months
sony z5 premium is 4k (i own one tooo)
+1 That’s the first thing I thought of when I read this.
scratch that , its only 2k, bah
Dual display, 2k x2=4k right? :P
2k x4 = 4k, no? :P
Doesn’t the Raspberry Pi already have a DSI interface?
does it matter? Consider this: you can connect to *anything with HDMI* because HDMI autonegotiates resolution
Only if the device works right…
I have bought one of those universal LVDS coverters from ebay without it being programed (cost a 1/3 of what a programed one did) and used some firmware image I painstakingly found on the internet… for the love of whatever you consider holy, I cannot get the thing to run in native resolution, the HDMI interface wants to run in all others but not this one, the problem seems to be in the firmware image, but it’s machine code, so I can’t modify it…
Yeah, but I don’t think drivers have been released yet.
yes, and you will NEVER be able to use it freely because of Broadcom
just like mipi CSI on pee, its there, but broadcom wont let you use it for anything other than their branded camera module using their binary blob
In all fairness, that’s just as likely to be the fault of the MIPI as it is to be Broadcom’s fault. As far as I’m aware, the MIPI interface standards are closed industry standards that requires you to pay a toll to MIPI in order to gain access to the “secret sauce”. I wouldn’t be surprised if the lack of CSI/DSI documentation is because of contractual obligations between Broadcom and MIPI that tie Broadcom’s hands.
There are more than enough legitimate closed source/binary blob issues, in regards to Broadcom. I don’t see a reason to tack this on them too if it’s this likely it isn’t really there fault.
There is no secret sauce – just look at SoC application notes & datasheets, presentations, training documents, Android kernel driver sources… All the knowledge to implement an FPGA MIPI DSI master is out there and is not NDAed.
Concerning Broadcom – IMHO it’s their corporate policy, they’ve never been too open about their stuff. If you look at datasheets of other SoC manufacturers, their MIPI interfaces are well documented, with open source drivers.
No one is asking broadcom for documentation, access to registers would be enough, people would reverse engineer and build clean open source implementation in no time
It shouldn’t be too complex to port it to the miniSpartan6+ I hope…
lucky guy, he got featured twice ;)
Thanks Mathieu & Brian ;)
i don’t think that was voluntary, but you’re welcome anyway ;)
No such thing as bad press? lol
Would this work with an iPad (or similarly large) display? It might make a cool secondary monitor.
iPad LCDs are connected through Embedded DisplayPort, and it accepts ordinary DisplayPort signals with just a passive(mechanical) adapter and some +20V power. Makes things fairly easy compared to many in the past.
it has already been done IN THE SAME WARSAW HACKERSPACE, so how about you link the original hack
and not commercial copycats?
this guy “http://dp2retina.rozsnyo.com/” is a pain to deal with .. bad communication .. not to mention he is business un-friendly … i would rather get my controller for ipad from Japan .. and is much much much cheaper.
Commercial copycats? We have done the DP2RETINA interface without any documentation to the actual screen back in 2012. Wiring up a display according according to datasheet is not hacking :)
When you say it’s been done. It’s not really because that’s a DisplayPort and not a hdmi port.
I need hdmi for my mobile monitor application as it can be found on nearly every device with a video out now also hdmi you can get cheep long leads of decent quality. Preferably a 5v power feed is the best due to the explosion in power banks for iPads.
This board is perfect. I just need someone to make one for me. I’m not sure I know what I’m doing with the code. I’d be pretty confident making the board possibly. But I’m in the dark with respects to code and software.
Can anyone help an enthusiastic soul??
google…could have even back when you asked this. there are display port to hdmi converters that go the rest of the way… or u know… buy a device with display port because it kicks ass. DP can pretend to be just about any standard you need it to be with a passive dongle.
This would be very useful to turn a zotac zbox pico into a true standalone computer.
This looks awesome!
Since this includes a frame buffer, maybe this can be adapted to convert an HDMI signal so it can be fed to the camera input of a RaspberryPi, for inexpensive uncompressed HDMI to .264 realtime hardware compression. Apparently, since the camera for the RaspPi is sychronized by the processor for each frame, and regular HDMI obviously provides it’s own sync, a frame buffer would be required…
Hey guys, new in the comunity. Im interested in know news of this proyect. Is still in development?
It would be interesting to be able to use smart phone as HDMI display, not just the screen. What I am looking for is a devise that codes the HDMI video to .264 or similar and feds it via USB to phone that decodes the .264 and all with minimal latency.
That’s what I’m looking for my self I’m trying to use a ipad screen. With a iphone ..
I just want it to have a digitizer port
Friggin Brilliant idea.
I have 5.5 inches HD IPS display how can I use in other media hardware??
is it possible to drive an ipod/iphone 960×640 display using only two lane DSI (like the RPI have) ?
does anyone know if i can use the sonys xperia z5 premium screen with a kit/module to connect it to an hdmi for a homemade vr headset?
and wich module/kit dou you recomment in this case?
My thoughts exactly. Have you had any feedback …
Has anybody tried the opposite? Making a converter so that any screen can be used with a phone motherboard (so people with broken $200 OLEDs can swap it out for an LCD instead?).
I am interesting in this topic too! I still need some time to figure it out. Is there any progress on your side?
it exactly what i’m thinking about, it been a long time since you poste this but did you give it a shot ?
is there any progress ?
Same, broken smartphone with 855 soc, would like to use it with a HDMI monitor…
Can’t find any fix :p.
Sounds good to me. I’ve got a broken pile here if anyone wants to experiment, mostly water damage but some just don’t work for unknown (mainboard hosed) reasons so unable to test the panels.
Just found your web page whilst searching for info on whether I could use an HTC Desire HD screen as a display for a Raspberry Pi. Do you know if this is possible?
what is the thing that is attached to the shield
What is the connection between the LCD and the shield?
Many tablet android phone users are still confused. Touchscreen broken tablet is different from the damage to the LCD. Both parts are different, LCD and touchscreen is a separate item, the touchscreen damage only happens on the screen (thin) at the top / outside only, not the LCD part in it. You can visit the insurance displayverzekering.nl display
Hi.. Is this system available commercially in open market..? If yes, how can I get one shipped to India.?
Sir i want use HDMI as output and mobile lcd port as input i.e from motherboard of the phone
Is there any chance of getting this to work with a 4k resolution phone screen?
Any way to buy these still? Or at least get a parts list and instructions?
Can this be reversed, I have a dozen mobile motherboards, I wanna know if a mobile motherboard can be made to output to HDMI
Hello! Does anyone have any ready rev1_top.bit file?
How about a board for the phone camera??
I have a broken Lumia 1020 and would love to make something out of the camera and screen… can someone help me with a parts list please!!
If I wanted to use a composite decoder IC, and drive a cheap smartphone screen to just display composite video (yellow RCA jack style) would that be easier than this, or like, impossible?
This is a great idea! Ideal for DIY projector enthusiasts who use 7-10″ LCD panels from tablets. It makes the final project way smaller!. Looking forward for further development of this project. Keep up the good work!
I’m new here. I have access to a bunch amoled screens from the galaxy tab am-t800 series, and I can’t find a controller board for the 10.5″ screen much less anything that Willy include the capacitive touch capability. Has anyone explored Samsung amoled tech here before?
Firstly i wish to congratulate you for developing all these hacks. I have a question. is it possible to develop a board that reverts the signal from “HDMI –>DSI ” to “DSI –> hdmi”? I make this question because i have a s7 edge, that, as you know, has no support for MHL neither displayport and i would like to connect it thru its lcd fpc connector.
Hey, Nice work.
i search this think for a HTC Desire Eye display to use it via HDMI on PC or Raspi
can u help me?
where can i get that board?
Any information about the inverse problem?: Connecting other displays to the smartphone’s display output? Or connecting phones from other brands/models to the same phone mb?
I am having this issue from time to time as I am the Techy/ sucker among my friends and family.
If you have found a solution let me know.
any idea if you can feed the Sony xperia z5 premium UHD LCD screen using this HDMI adapter device?
Or an alternative device?
And if yes, at which FPS?
Do you know/think if there is an option to drive it with 60fps?
Good job, it should be commercial and put to the market
I would Like to have it the other way round.
Using the internal Port to hdmy could Turn any Borken flagshiff Phone into a powerfull PC alternativ.
Sadly using usbc Displayports makes you lose computing Power while working with you’re device 😟
Does the raspberry pi accept touch input from the screen?
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