DIY: Custom Light Control for Tesla Factory Offroad Lightbar and/ or Aftermarket

[Coolhandz]

This is a really cool project. Does it show in the UI too? If so, I cannot wait to see this come as a fully integrated setup. Those lights look so much brighter than the OEM ones. Amazing engineering and hacking on going on here.

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[mongo]

This is a really cool project. Does it show in the UI too? If so, I cannot wait to see this come as a fully integrated setup. Those lights look so much brighter than the OEM ones. Amazing engineering and hacking on going on here.

The OEM are bright and super directional. To see them off axis, I left the lightbar in bubble wrap.
Of course, more lights is more brighter .
Here it is being run from the UI.

 

[mitch9]

He has a 48V 50" lightbar, but it needs to mount on his MARS Expedition Rack, and it looks to be a sealed unit with a 2-wire 48V input, not sure it could be taken apart and get to various segments, maybe one large PCB inside, hard to tell without tearing it apart. I'm looking for a permanent mounted solution, I don't mind building the electronics, but it has to look good as well when completed. Thanks, Mitch

 

[mongo]

He has a 48V 50" lightbar, but it needs to mount on his MARS Expedition Rack, and it looks to be a sealed unit with a 2-wire 48V input, not sure it could be taken apart and get to various segments, maybe one large PCB inside, hard to tell without tearing it apart. I'm looking for a permanent mounted solution, I don't mind building the electronics, but it has to look good as well when completed. Thanks, Mitch

Yah, I envisioned the long white with flanking short yellows and an external module controlling them mounted to the cross bar (versus integrated into the light itself).
If wanting a six segment setup, the Amazon specials are probably the way to go mounted to a crossbars with separate module. I made a three output prototype, but it's easy enough to go to six if you don't need OEM bar control and you aren't looking for 8 amp capacity on every output. (Demo used two modules for 6 outputs).

Might be able to hide electronics in the B-pillar and run the wiring through the grommet.

Off the shelf weatherproof housing:

https://www.digikey.com/en/products/detail/cinch-connectivity-solutions/5810130090/7650220

https://www.digikey.com/en/products/detail/cinch-connectivity-solutions/5810112011/6199344

 

[JCERRN]

Tesla lightbar communication is controlled by a pair of LIN messages sent at 10ms intervals.
Control:
ID: 0x0A
Length: 8 bytes
Data: six values 0-100, packed at 10 bits each



Status:
ID: 0x0B
Length: 5 bytes
Data: temperature, voltage, and other status
However, you can respond with zeros and the truck accepts it as proof of life.

Diagnostics:
ID: 0x3C 0x3D
Length: 8 bytes
Data: various propriety including software version
Truck will complain if these are ignored, but still allows the UI to function.

Here's an Amazon list of the parts needed to make your own 2 output controller:
https://www.amazon.com/hz/wishlist/ls/36PX96UY981FV?ref_=wl_share

One DCDC converter provides 5V to the ESP32 via the 5V pin (the listed module diode ORs it with the USB feed, others don't). The second is set for 15V to power the LIN transceiver.

If your micro is 3.3V (like the ESP32), you should remove the 5V pullup resistors (R4, R6) from the LIN transceiver board (but mine survived with them).

Parts handy for development and testing: https://www.amazon.com/hz/wishlist/ls/3N0GP3YZM3SFZ?ref_=wl_share

Using a second LIN transceiver, you can control the lightbar directly allowing custom patterns instead of just dimming levels.

Strong work! I’m still curious how the truck identifies it as an OEM, and if there is any way to spoof that. The other thing that I noticed is that once the OEM light bar has been installed, the graphic and interface don’t seem to go away even at the bar is disconnected electrically. I wonder if once you have the interface established if you can control other light bars with that same interface

 

[mongo]

Strong work! I’m still curious how the truck identifies it as an OEM, and if there is any way to spoof that. The other thing that I noticed is that once the OEM light bar has been installed, the graphic and interface don’t seem to go away even at the bar is disconnected electrically. I wonder if once you have the interface established if you can control other light bars with that same interface

There are two levels of confirmation.
The first is responding to 0B messages. If you do that then the truck thinks a lightbar is installed.
The second is 3C/3D diagnostics messages. These get sent on vehicle wake up and during software updates. The query/response format is straight forward, but the data values are unknown as to meaning. Wrong or missing responses cause version errors to show up in service mode.

The code does spoofing based on recent software version and the truck sees it as stock. And so you can run whatever you want from the truck's UI (post #17).

The truck won't prompt about lightbar removal if you only disconnect it. It also has to be powered on. (At least it was that way last month, there was a really twitchy version that would complain about the OEM bar briefly, but that seems resolved).

Logging behavior:

 

[JCERRN]

The hardware is really just post #7 (unless you make your own PCB).

The software does the magic, here's a copy of it. Readme is a little stale, I pulled out BLE serial due to having a web server.
Password.example.h needs to be renamed to password.h and filled in with your credentials.
Minimal comments .

<- All the aftermarket manufacturers reading this thread

 

[mongo]

<- All the aftermarket manufacturers reading this thread

More power to them!
This was a hobby project I made because I want it to exist. However, I don't want to be on the hook for service/ warranty, nor in the event Tesla changes the communication protocol and renders them all useless.

Further, I don't know if there is really a profitable business case to be made.
The tech is really simple to duplicate, too high a price will drive undercutting. Plus, there aren't that many Cybertrucks and Beasts already have lightbars. So addressable market is AWD owners who want to run multiple individually controlled lights.
BOM for a three output module is under $100 including wire harness. So if things went well at a $199 price point and 1,000 customers you gross $100k. But someone comes in at $120 and profit shrivels up.
If someone is already making lightbars and all it takes is adding LIN, that's way more cost effective and can be a product on it's own.

Assembly (solder stencils are awesome!):

 

[jjban]

How to display the light bar interface on an AWD. Could you explain it more ? I have no programming experience.

 

[mongo]

How to display the light bar interface on an AWD. Could you explain it more ? I have no programming experience.

Basically, you need a module on the LIN bus that sends the truck the 6 byte (5 data , 1 checksum) message it expects when they truck requests it.
That causes the truck to activate the lightbar UI elements.

Imagine the truck keeps saying "how are you doing?"
The module needs to say "I'm fine" (or even "arrrrgggg").
When it does, the truck goes "OK, there's a lightbar, I'll let the driver control it"

 

[mitch9]

Looks like you built a custom PCB to fit in that off the shelf case you are using, is that using surface mount components? looks like it might be.. are the gerbers somewhere? or is JLPCB perhaps making it for you? curious. Thanks, Mitch

 

[Gaximus]

Tesla lightbar communication is controlled by a pair of LIN messages sent at 10ms intervals.
Control:
ID: 0x0A
Length: 8 bytes
Data: six values 0-100, packed at 10 bits each



Status:
ID: 0x0B
Length: 5 bytes
Data: temperature, voltage, and other status
However, you can respond with zeros and the truck accepts it as proof of life.

Diagnostics:
ID: 0x3C 0x3D
Length: 8 bytes
Data: various propriety including software version
Truck will complain if these are ignored, but still allows the UI to function.

Here's an Amazon list of the parts needed to make your own 2 output controller:
https://www.amazon.com/hz/wishlist/ls/36PX96UY981FV?ref_=wl_share

One DCDC converter provides 5V to the ESP32 via the 5V pin (the listed module diode ORs it with the USB feed, others don't). The second is set for 15V to power the LIN transceiver.

If your micro is 3.3V (like the ESP32), you should remove the 5V pullup resistors (R4, R6) from the LIN transceiver board (but mine survived with them).

Parts handy for development and testing: https://www.amazon.com/hz/wishlist/ls/3N0GP3YZM3SFZ?ref_=wl_share

Using a second LIN transceiver, you can control the lightbar directly allowing custom patterns instead of just dimming levels.

Does the communication work both ways. Say turn on the lightbar, from a signal other than the touch screen. I’d love to have mine turn on with the drl.

 

[mongo]

Does the communication work both ways. Say turn on the lightbar, from a signal other than the touch screen. I’d love to have mine turn on with the drl.

Nope, no signals on LIN other than lightbar communication control.
And S3XY buttons doesn't have a Cybertruck version yet to leverage.

 

[mitch9]

I believe I found another way to use Mongos design.

If you use the lightbar from xkglow, it already has “app control” of the lightbar, to run LEDs or use it in DRL mode.

Using Mongos LIN interface, to communicate with the Cybertruck, allows the truck to be aware of the lightbar/control it, for lightshows etc. Mongo has a web server as the interface to a phone web browser, so if some work is done, his ESP32 could connect via WiFi or Bluetooth to the xkglow, and at a minimum, allow for on/off of 2 macros that could be triggered.. by doing it this way, only the LIN portion of Mongos controller is needed, the rest is web client emulation to talk to the xkglow.. they also have their controller external, so it could possibly be hacked directly as well, to allow the ESP32 to control it. I like it, uses an existing $1200 lightbar, and can emulate the factory functions for the lightshow

Mitch

https://store.xkglow.com/catalog/pr...esla-cybertruck-rgbw-chasing-drl-app-control/

 

[L3it3R]

@T Sportline needs to buy these from you

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