okenido
Posts: 78
Joined: Thu Aug 02, 2018 11:47 am

New display with better quality possible ?

Tue Dec 18, 2018 2:17 pm

Hello,

I'd like to know if the Raspberry Foundation is planning to make a new model of the 7 inch touch screen. The current one has a quite poor image quality compared to the current displays we find in products like smartphones, tablets and tactile laptops.

Problems sorted by importance from high to low, in my opinion :
- Poor viewing angles, especially vertical ones. Color shift is huge. Horizontal angles are okay-ish
- Low resolution. 800x480 is far from current standards
- Colors aren't very accurate and are produced by the use of a noticeable dithering

Is a new version planned for the future ? I plan to ship a product using the official 7 inch screen, but it feels a bit underwhelming for 2018 / 2019.

If i need to look for a separate LCD/touch screen, is there a way to connect it to the RPI with the same ribbon connector as the official screen ? It provides so much ease of integration, compared to a separate HDMI/USB touch screen that doesn't easily work in bare metal environment...

scotty101
Posts: 4165
Joined: Fri Jun 08, 2012 6:03 pm

Re: New display with better quality possible ?

Tue Dec 18, 2018 2:35 pm

The Raspberry Pi Foundation never (almost never) share their product release road map. Odds are you won't find out until one goes on sale.
Electronic and Computer Engineer
Pi Interests: Home Automation, IOT, Python and Tkinter

fruitoftheloom
Posts: 25261
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: New display with better quality possible ?

Tue Dec 18, 2018 2:45 pm

okenido wrote:
Tue Dec 18, 2018 2:17 pm
Hello,

I'd like to know if the Raspberry Foundation is planning to make a new model of the 7 inch touch screen. The current one has a quite poor image quality compared to the current displays we find in products like smartphones, tablets and tactile laptops.

Problems sorted by importance from high to low, in my opinion :
- Poor viewing angles, especially vertical ones. Color shift is huge. Horizontal angles are okay-ish
- Low resolution. 800x480 is far from current standards
- Colors aren't very accurate and are produced by the use of a noticeable dithering

Is a new version planned for the future ? I plan to ship a product using the official 7 inch screen, but it feels a bit underwhelming for 2018 / 2019.

If i need to look for a separate LCD/touch screen, is there a way to connect it to the RPI with the same ribbon connector as the official screen ? It provides so much ease of integration, compared to a separate HDMI/USB touch screen that doesn't easily work in bare metal environment...

If you have developed a product then use the CM3 with a custom baseboard so you can then choose a suitable Display....
The information is out there....you just have to let it in.

My other Linux machine is a ChromeBox

okenido
Posts: 78
Joined: Thu Aug 02, 2018 11:47 am

Re: New display with better quality possible ?

Tue Dec 18, 2018 3:21 pm

I've thought about the CM3 but unfortunately it's not very competitive price-wise, and designing a custom baseboard is far from easy (and adds additionnal cost). The problem here is getting a nice quality touch display and interfacing it with the RPI through its ribbon connector.

User avatar
RaTTuS
Posts: 10703
Joined: Tue Nov 29, 2011 11:12 am
Location: North West UK
Contact: Twitter YouTube

Re: New display with better quality possible ?

Tue Dec 18, 2018 3:58 pm

you can buy 10" hdmi touch screen for £90 ....
How To ask Questions :- http://www.catb.org/esr/faqs/smart-questions.html
WARNING - some parts of this post may be erroneous YMMV

1QC43qbL5FySu2Pi51vGqKqxy3UiJgukSX
Covfefe

W. H. Heydt
Posts: 14031
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: New display with better quality possible ?

Tue Dec 18, 2018 5:33 pm

The only hint that has ever been uttered (that I know of), was Eben Upton musing about following the 7" display with a 10" one. Given the trouble it took to get the 7" unit to market, I'm not surprised that the 10" has never appeared (much as I wish it would...I could use 2 or 3 of them). And there may be more interest in going smaller, rather than larger.

Part of what drove the choice of the current 7" display was it being "industrial grade" (decent service life, not meant to be replaced every year or two, like a cell phone) and being one that would stay in production for several years (again, unlike cell phone screens). See the issues with the Pi camera modules for reasons for those sorts of decisions.

As for screen resolution...there are limits to what can be handled by the VC4 over the DSI interface. IIRC, a limit of 720p has been mentioned, and that is still far below what current cell phones are using.

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 10293
Joined: Wed Dec 04, 2013 11:27 am
Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: New display with better quality possible ?

Tue Dec 18, 2018 6:08 pm

W. H. Heydt wrote:
Tue Dec 18, 2018 5:33 pm
As for screen resolution...there are limits to what can be handled by the VC4 over the DSI interface. IIRC, a limit of 720p has been mentioned, and that is still far below what current cell phones are using.
60fps 720P 24bpp RGB pretty much maxes out the two exposed DSI lanes. (1.3Gbit/s ignoring blanking periods, and DSI can carry 1Gbit/s per lane).
60fps 1080P 24bpp RGB requries just over 3Gbit/s, so at least 3 lanes (more likely 4).
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

aBUGSworstnightmare
Posts: 2442
Joined: Tue Jun 30, 2015 1:35 pm

Re: New display with better quality possible ?

Wed Dec 19, 2018 6:39 am

If you want to use MIPI DSI interface you will have to develop your own baseboard as the standard Pi only exposes 2-lane DSI interface.
Higher resolution displays need 4-lanes (i.e. for FHD), that's why the standard Pi could not be connected to them at all.

If you want to go that way here are two links for you:
https://github.com/anholt/linux/wiki/Ra ... lay-panels
https://github.com/torvalds/linux/blob/ ... chscreen.c

Touchscreens use either I2C or USB interface (well, there might be other interfaces as well). Either mimik the official touchscreen, write your own driver, or use an 'internal' USB connection on your base board (i.e. USB is on the touch FPC --> no external USB connector needed; example is here i.e. viewtopic.php?f=29&t=228824)

Designing a custom CM3 baseboard is not such a big deal. It's with the effort as it gives you the flexibility you need.
I've made one for dealing with displays
IMG_0685.jpg
Google Nexus 7in (1280x800 portrait mode) and 18.5in Full-HD (1920x1080; rotated to portrait) - both connected directly to LVDS4CM3L expandable baseboard.
If you dig into the spec of the touch screen you can add your own controller for it too.
IMG_0685.jpg (137.76 KiB) Viewed 2315 times

User avatar
bensimmo
Posts: 5057
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: New display with better quality possible ?

Wed Dec 19, 2018 7:40 am

Did you get the digitiser on the Nexus screen working? I remember the board you developed but can remember if the digitiser was usable.

User avatar
Gavinmc42
Posts: 5085
Joined: Wed Aug 28, 2013 3:31 am

Re: New display with better quality possible ?

Wed Dec 19, 2018 8:25 am

The new PiTop is interesting me, Full HD.
Would be nice if there was a smaller tablet size display with same res.
IPS TFT or even OLED.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

aBUGSworstnightmare
Posts: 2442
Joined: Tue Jun 30, 2015 1:35 pm

Re: New display with better quality possible ?

Wed Dec 19, 2018 4:04 pm

bensimmo wrote:
Wed Dec 19, 2018 7:40 am
Did you get the digitiser on the Nexus screen working? I remember the board you developed but can remember if the digitiser was usable.
PCAP will require development of a controller board. As I only have one google Nexus 7 gen 1 display I see no reason why I should spend time and money in developing one.
Means: No! digitizer is not working as I was only interrested in the IPS WXGA display module. At the time of buying it, the full setup (coverglass+PCAP+LCD display) was cheaper than the LCD module only ... that's why I bought it.

Return to “Official Foundation Display”