Custom Touchscreen LCD Gauge: Comprehensive CAN Network Access for Enhanced Vehicle Monitoring

[Bug2th]

So. What would it take to create an app that can use the existing display through CarPlay or similar?

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[omfgzilla]

wish we could code it into our hud

 

[razorlab]

So. What would it take to create an app that can use the existing display through CarPlay or similar?

You can do this currently with the generic OBD2 stuff.

https://ontrackapps.co.uk/

 

[Surebob]

So. What would it take to create an app that can use the existing display through CarPlay or similar?

You would still need a custom board with dual can controllers if you want to tap into all the data, otherwise it’s possible with enough effort.

another option is to create a HDMI-LVDS bridge and hijack the video signal to the screen, but information on current gen LVDS protocol for the screen is sparse. I know it’s FD Link, but need to know the LVDS details and unfortunately I haven’t been able to find any data sheets on the LCD itself.

if anyone knows let me know, that was the initial plan for this project.

 

[S2k]

This is an interesting thread!

Is it definite that the display does not have access to the CAN bus? I would have thought it does, but the thing that messes it up would be the displays embedded processor’s SW drivers not exposing anything useful from CAN to an app running in CarPlay. I can see your idea of sharing the video link with something custom as a way to re-use/overlay on the display though! Is FD not something pretty simple like a 3x 8:1 serialisation link of the RGB using differential (LVDS)? You considered using something like say a Zynq as a solution or would that be expensive compared to your design?

The table done by @razorlab showing the CAN bus mappings is also interesting stuff! I may have a dig around my office and see if I can find a CAN bus analyser to have a play with it sometime!
(I have never messed around with automotive stuff before!)

 

[Bug2th]

I don’t know much about the communication of data but I was thinking you get the canbus data to the iPhone via Bluetooth, etc and have the phone app push the data onto the car display through CarPlay - not sure how laggy that might be.

 

[Mauiboy406]

interested to see your finished product. Please keep us posted.

 

[Surebob]

S

I don’t know much about the communication of data but I was thinking you get the canbus data to the iPhone via Bluetooth, etc and have the phone app push the data onto the car display through CarPlay - not sure how laggy that might be.

So traditionally you would send the data from a Bluetooth OBD2 dongle, which won’t be able to access all the data. If only OBD2 PIDs are sufficient for you then this is very much doable. But if you want all the data, you would still need to build a custom Bluetooth board with dual can controllers and splice in to the passenger footwell to both can modules.

 

[Surebob]

This is an interesting thread!

Is it definite that the display does not have access to the CAN bus? I would have thought it does, but the thing that messes it up would be the displays embedded processor’s SW drivers not exposing anything useful from CAN to an app running in CarPlay. I can see your idea of sharing the video link with something custom as a way to re-use/overlay on the display though! Is FD not something pretty simple like a 3x 8:1 serialisation link of the RGB using differential (LVDS)? You considered using something like say a Zynq as a solution or would that be expensive compared to your design?

The table done by @razorlab showing the CAN bus mappings is also interesting stuff! I may have a dig around my office and see if I can find a CAN bus analyser to have a play with it sometime!
(I have never messed around with automotive stuff before!)

The display itself does not have nor needs to have access to canbus, the display is connected to the head unit through a HSD 6 pin (4+2) cable that carries power on the 2 pins and video data on the 4 pins. The display does not run CarPlay or anything else on it, it is simply an LCD, now on the other hand the head unit does have access to ONE of the can busses and uses this connection for a a lot of different functions.

To answer your other question, yes FPD link and lvds are fundamentally “simple” but you need to first of all know what version of FPD link your display runs (it is speculated that NBT EVO runs FPD Link 2) and you would probably need a couple of prototype revisions before you can get any signal to the LCD, not to mention the meticulous importance of making sure all your high speed signaling like hdmi and lvds are routed properly, your boards impedance is correct etc.

It will take some time, but eventually I’ll get it right.

If you would like to do this yourself, you are more than welcome to purchase one of the Anydream CarPlay/android auto MMI boxes, and using the HDMI input on them. But I don’t like this solution as it’s a janky solution, I prefer a much cleaner OEM+ solution that doesn’t also come with all the extras that I don’t need.

I want to achieve a product where it will integrate into the vehicle seamlessly, you start your car and drive off, you want to switch to the gauges all you have to do is hold a button on the steering wheel, and the switcher will switch the signal from your OEM signal to the AUX signal hijacking your display and displaying the user interface.

then of course the experience also depends on the software that I will develop, UI UX etc…

 

[Spart]

It looks like you're not a manual owner so this may not have occurred to you as a feature to have, but give it a nice programmable shift light.

The manual cars really need a shift light for track work.

Even if there was a mode that turned the whole thing a solid color that would work great, as it's easy to monitor in your peripheral vision.

Something like green for 3000-5500RPM, yellow for 5500-6500 RPM, and flashing red at 6500+ RPM would be a good start. But make it configurable of course. If it's possible, the range of the yellow zone should tighten with higher gears.

It would also be nice to have a mode that left the regular gauge displayed up to the defined shift point and then started flashing the whole thing red once the shift point came up.

 

[dn00]

Working on something similar but as an interface to bm3's odb agent which exposes all that sweet juicy parsed data over local websocket. Tried my hand at reverse engineering can frames. That was not fun.

 

[rwense]

Hey OP! Just curious has there been any headway on this? Lmk if you have any socials we can follow

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