RGBhv Resolution

virnoche

TS Rookie
Greetings! I have a simple question pertaining to automobile Navigation systems. My Infiniti has a head unit that controls everything pretty much from HVAC to Navigation Radio, DVD etc. I have researched all the schematics etc and would like to upgrade my OEM screen to a higher resolution in preparation for adding an Android box in between the head unit and the screen.

The current screen resolution is either 400x234 or 480x234 I am not 100% certain but it is definitely one of those. I would like to replace the LCD to a 800x480 screen. The OEM screen has a driver board that connects in between and takes the touch signal 4 wire resistive and the 50 pin RGB LCD and puts it on the system wiring and buss.

What actually drives the resolution? Does the main head unit send out a 400x234 signal or is the RGB signal raw and the board on the LCD module interprets it and sends the correct timing and resolution to the LCD panel?
 

neeyik

TS Guru
Staff member
It's possible that the head unit is controlled by an Intel Atom SoC, as Infiniti starting using them around 2013. Those chips use a PowerVR GPU so it's more than capable of handling that resolution - however, and this is the point for your query, it needs to be told to output at a given resolution and this will be done via the nav systems OS. So unless you can gain access somehow to a copy of the OS that allows you to adjust various settings, you're pretty much left with making your or finding somebody to craft an upscaling circuit. However, it is possible that the Atom SoC just runs at a set resolution and the LCD module contains something like a Toshiba signal processor to handle the display, but again, it needs to be instructed to operate for a given output; it doesn't automatically change things based on the display attached to it.
 

virnoche

TS Rookie
It's possible that the head unit is controlled by an Intel Atom SoC, as Infiniti starting using them around 2013. Those chips use a PowerVR GPU so it's more than capable of handling that resolution - however, and this is the point for your query, it needs to be told to output at a given resolution and this will be done via the nav systems OS. So unless you can gain access somehow to a copy of the OS that allows you to adjust various settings, you're pretty much left with making your or finding somebody to craft an upscaling circuit. However, it is possible that the Atom SoC just runs at a set resolution and the LCD module contains something like a Toshiba signal processor to handle the display, but again, it needs to be instructed to operate for a given output; it doesn't automatically change things based on the display attached to it.
This is in a 2008 so that would rule out the SoC. I figured this wasn't going to be easy. The display itself is indeed a Toshiba NEL75 AB1J233A k8g16W6. I guess I'm SOL! Sucks that I can buy LCD displays for under 20 bucks but no way to adjust the resolution in between. I have looked at a few RGBhv to RGBhv scalers where I thought I could maybe put in between the head unit and the factory display board but not sure if the display board would just scale it back to the old resolution ….. DANG IT!!!
 

virnoche

TS Rookie
It's possible that the head unit is controlled by an Intel Atom SoC, as Infiniti starting using them around 2013. Those chips use a PowerVR GPU so it's more than capable of handling that resolution - however, and this is the point for your query, it needs to be told to output at a given resolution and this will be done via the nav systems OS. So unless you can gain access somehow to a copy of the OS that allows you to adjust various settings, you're pretty much left with making your or finding somebody to craft an upscaling circuit. However, it is possible that the Atom SoC just runs at a set resolution and the LCD module contains something like a Toshiba signal processor to handle the display, but again, it needs to be instructed to operate for a given output; it doesn't automatically change things based on the display attached to it.
I think you nailed the Toshiba processor! This system does indeed overlay DVD functions XM Radio etc as well as the HVAC information so This makes a lot of sense. Is it possible to edit that board?
 

neeyik

TS Guru
Staff member
Hmm, none of those codes are coming up on a search - do you have an image for the whole board that the ic is on?
 

neeyik

TS Guru
Staff member
Still struggling to find any datasheets related to that product - plenty of websites are offering that product but nowhere seems to contain anything regarding its operation.

However, you can see how the output from the display processor needs to work by looking at this document:

https://www.nxp.com/wcm_documents/techzones/microcontrollers-techzone/Presentations/graphics.lcd.technologies.pdf

So the problem to resolve is that the head unit's output signal will be timed for a 480 x 234 resolution - directly attaching a higher resolution panel would probably either result in the frame being tiled across the 800 x 480 panel or you just get a quarter of the panel filled, because there is no column/row information after c480 and r234, respectively.

This is why the head unit would need to be put through an upscaling circuit to match the higher resolution panel (something way beyond my electronics knowledge).
 

virnoche

TS Rookie
Still struggling to find any datasheets related to that product - plenty of websites are offering that product but nowhere seems to contain anything regarding its operation.

However, you can see how the output from the display processor needs to work by looking at this document:

https://www.nxp.com/wcm_documents/techzones/microcontrollers-techzone/Presentations/graphics.lcd.technologies.pdf

So the problem to resolve is that the head unit's output signal will be timed for a 480 x 234 resolution - directly attaching a higher resolution panel would probably either result in the frame being tiled across the 800 x 480 panel or you just get a quarter of the panel filled, because there is no column/row information after c480 and r234, respectively.

This is why the head unit would need to be put through an upscaling circuit to match the higher resolution panel (something way beyond my electronics knowledge).
Gosh you have been helpful! Thank you very much for that. You were able to find that board online? I couldn't find boo!
 

neeyik

TS Guru
Staff member
Only the likes of Alibaba selling the display unit - my gut feeling is that it was custom Toshiba unit for Nissan, which would explain why so few of the components come up in searches.

You'll probably find it easier, but not cheaper, to just scrap the entire head unit and display, and replace it with the same from a newer model. The wiring looms will be different, so you'll need to rejig the connections, but I found this as a very rough guide:

https://www.cargurus.com/Cars/Discussion-t35159_ds918040
 

virnoche

TS Rookie
Only the likes of Alibaba selling the display unit - my gut feeling is that it was custom Toshiba unit for Nissan, which would explain why so few of the components come up in searches.

You'll probably find it easier, but not cheaper, to just scrap the entire head unit and display, and replace it with the same from a newer model. The wiring looms will be different, so you'll need to rejig the connections, but I found this as a very rough guide:

https://www.cargurus.com/Cars/Discussion-t35159_ds918040
LOL! I read that one too! I have already gone as far as trying to swap everything out but the actual Can Bus changed I believe in 2012 so that rules that out also. Thanks again for all you have done. I will probably just get this device and just live with the shitty Resolution!
 

neeyik

TS Guru
Staff member
Or just buy a 7" smartphone or phablet, and just stick to the Nissan infotainment screen ;)