Prototype HDMI Enable Hardware Works!
 

I will be updating this top post as progress is made!

Original Post

I have some exciting news to report to you guys!

I've spent the last couple months reverse engineering my Fit's CAN bus, building some hardware, and programming a device to enable HDMI input while not in park. Today, I finished up some prototype code, plugged it all in AND IT WORKS! I have successfully tricked the head unit into thinking its in park! Best thing about it is the reverse camera still works fine, since its a totally separate signal from the one I am messing with.

Here's my video proof: https://www.youtube.com/watch?v=ffWo...ature=youtu.be

I still have a ton of documentation work to do on the Github repo (see the video description if you are interested) and a couple more tests. I need to see if the unit enables all the features that get blocked out when you are moving. I think it should work without additional code, but I want to make sure!

Next task after all that is to design a custom circuit board to house all of this. Then we can talk about beta units :eek: :thumbups:

I'm going to start another thread soon with a technical discussion if anyone is interested in CAN bus data, or any of the other technical aspects of this project.

Also, I would like to thank two users on here for their ongoing motivation and help with this project: jhub908 and Bassguitarist1985. Thank you, thank you, thank you!

I'm off for a beer and a scuba diving trip :)

Update 10/2/15: Prototype PCBs and parts have been ordered and will arrive in less than week!

Update 10/5/15: I'd like to bring up the topic of donations.

Up to this point I have rejected the idea of donations since I was unsure as to whether I could actually get this thing working, but I am at a point now with my hardware that I am confident that I can deliver a working piece of hardware! If anyone is feeling generous and wants to buy me a cup of coffee to fuel my late night PCB design and soldering binges, I would greatly appreciate it :D

I think Paypal is probably the most convenient way - my Paypal email address is my username @gmail.com. Please choose "friends and family" when asked. If there is a more convenient way to give please let me know and I will accommodate as best I can! (bitcoins, venmo, whatever)

Thanks!!

Thank you so much! I really appreciate all the hard work you and everyone involved had put into this. I can't wait to see it once everything is all said and done. :thumbups:

Enjoy your beer and scuba trip :)

Dude i owe you my entire 5 gallon batch of home brew brown ale im kegging right now!! You rock buddy!

Some of the other restricted features such as seeing the read out of the text messages that come in from your phone, using the screen to dial and edit any settings of the HU are a few that come to mind.

My assumption and hope is that the system status condition via CANbus data that you are changing before it hits the head unit from the body CAN data is going to enable every setting because if it is available in park then all of those settings should be available.

Another interesting part is to see if the speed variable volume control will still operate. Not that it's a big deal but I believe it may be disabled because the head unit always thinks it is in park. Don't rack your brains too much on this feature as I barely notice it myself and maybe that was the intention from Honda but if it is not present then I don't much care I'd rather have the Google Maps being able to mirror through my HDMI. Keep me posted and PM me on the next development and when you are ready to do beta testing with your refined breadboard.

I hope you realize that this forum is going to explode with joy once they see this post because it doesn't just open the door for HDMI mirroring but it also opens the door with your decoded CANbus data map to do other things both good and evil I would imagine.

Cheers!!

This might be the first fit-related news that I have ever been excited about!
You rock.
When using google maps, does it switch over to the "phone call" screen when audio triggers?

Based on the hex key condition codes that Ducktapemaster decoded it should not. If the HU thinks its always in park the HU has all the functions in that state while driving in theory.

The next thing he has to test is if the "park" status condition is "connected" to any other process such as speed volume control and the various other minor features disabled while moving showing the "saftey warning." If they truly are not connected then he has essentially unlocked the entire HU.

In the event the park and SVC are connected processes the worst is SVC will not work, the rest of the functions in theory should be available while driving as they are in park. Im 99% confident the lanewatch is uneffected as well. The backup camera which he confirmed. Those two feeds are through the B-CAN, except the backup camera trigger is via the reverse light signal, while the lanewatch is through the GCU (gauge control unit) which communicates through the B-CAN.

Complex shit but knowing his prototype works really does open the possibility for more potential intercept coding to unlock the HU completely under all driving states/conditions.

Thank you Ducktapemaster--and all who helped--for persevering on this challenge. I wish I were technically competent to help, but I have no programming experience. I do have background as a tech in component-level PCB repair and own a hot air tool (I can do the older style smd, but not bga), and I would be able to stuff boards for prototypes, if such help is needed down the road.
Woo hoo!

This makes me so excited! Many thanks for jumping on board and getting this going! Now I can put movies on the screen while I'm driving instead of setting up my buddy's laptop or my tablet (which rests perfectly on the climate control knobs, btw). Not that it's much safer, if at all....

Not to be that guy, but any way I could secure a beta unit when the time comes? :D

Since I don't have an iPhone at the moment, how does the HondaLink navigation app work?

NOTE: Because it was confusing after I reread what I wrote... the below is me wondering how the stock apple HondaLink nav app works and interfaces with the head unit...
You plug it into the HDMI, but does the touchscreen work? Or is it display only (like this solution)? Can't imagine the touchscreen working unless the app is communicating with the head unit via Bluetooth for the touch data stream as well...



Should modify one of those inkjet printers to print out circuit boards :)
And yes I am interested in how you are capturing and reading the CAN BUS data :) Hondas use the two wires right... German cars use fiber optic CAN BUS :x

There is no android support from Hondalink, nor does there seem to be any support in the future. Supposedly Android Auto is going to be broadly pushed out to the Honda lineup, but thats a bunch of double talk BS.

To answer your other questions: The Hondalink app uses bluetooth as an interface for the touch screen. The HDMI interface is dumb, it only mirrors the display of your phone. This is not to be confused with "mirrorlink" which is a separate protocol interface all together. The HondaLink app via bluetooth sends an "unlock" code to mirror the phone letting the phone be mirrored as long as the app is in the foreground. Another forum member recently proved with a rooted iOS Iphone 5S that you can mirror anything else on the phone with Watchdog Pro. This is unfortunately not available for android.


What Ducttapemaster is proposing is unlocking the mirror function while driving via the HDMI, the touch screen would not accept any input functions, only mirror the phone. This alone is a huge unlock since it could be years (really) before Google (OOA), Apple, and MirrorLink (Car Connectivity Consortium) finish battling it out on who will dominate the Infotainment industry.

To be able to mirror google maps will be a huge plus if all that is needed is his proposed prototype interface interrupter hack device. I'm looking forward to working with Ducktapemaster helping him in any way I can to develop his device!

Amazing work. So this means we would have to take the head unit out to plug this into the back, correct? Any chance this will work for 6MT users as well?

Thanks!

Yes, this unit would plug in between one of the connectors and the head unit. I'm trying to figure out how to power it as well, which may require a cable splice, or a separate cable interrupter of sorts. I'm still debating as to what is easier. I want this to be as plug and play as possible, but power is on a different connector....

It should! I'm trying to design this to be platform agnostic. Its likely that this will work on other Honda models as well, and with some or no modification, 2016+ models! However I don't own any of these cars, so I will definitely need help from the community on this. There's some information to be gleaned from the Honda service website as well, but I will need to sign up for another subscription.

Ducktapemaster, we can discuss getting adapter parts in bulk from Mouser.com. I have an account with them. Depending on which adapters and how many wires are needed maybe we can figure out a coopertive how to mass produce them for the Fitfreak forum members only perhaps.

I'm happy to talk about that. I still have some engineering work to do on this before I start designing boards (mostly related to cross-trim, cross-model functionality) however. I've already purchased 20pcs of both male and female connectors and I'm looking at board design currently.

Also, I need to somehow address the legal questions around a device like this. Consider that this functionality was removed due to Honda following some voluntary guidelines published by the NHTSA for helping reduce distracted driver problems. If someone puts one of these in their car, puts on something distracting on the display and crashes, I need to be absolutely certain that none of that responsibility comes back on me. I briefly looked at how other groups/companies deal with this with similar devices, and it all looks like they have some sort of disclaimer on their website stating that their video-enable devices are meant to be used while the vehicle is in park, blah, blah, blah - but consider that they are not selling their devices under the premise of disabling a safety feature! I definitely am. This worries me a bit to be honest.

Also, I don't know how using something like this can affect one's insurance. I don't think it counts as a "modification" that they typically are interested in knowing about, like race modifications, but you never know. Also, what about factory warranties? Its likely you will have to splice into the power wires behind the dash. Does that void some or all of your car's warranty?

All questions I need to answer before I even distribute a single one of these. Sorry to sound like a buzzkill, but I'm actually seriously thinking about all of this. I'm a hobbyist, not a lawyer!

Ducktapemaster, you are absolutely correct that the NHTSA made these restrictions on HU in all vehicles, and auto makers complied. Disclaimers are a good way to start. What I will point out is that being your device will "potentially" disable a "safety feature" if used improperly, then the onus falls back to the user, not you the creator/seller who made a clear warning not to be used under unsafe conditions.

The next thought I will articulate is that if you are looking to make a profit on your device and mass distributing, e-commerce website claim as a small business etc, you may encounter potential resistance from big corporations like Honda, DOT, NHTSA, etc. HOWEVER...If you were to provide all the necessary parts and steps to create a device on a public forum, well this is now free speech, and the users who make this device use it at their own risk. I believe all work should be compensated in some form. People seem to be less anal about things when money is not involved.

Let me give you a scenario from another forum I am on. I repair generator control boards on smokstak.com. I was able to reverse engineer some common but particularly expensive PCB's. Rather than spend the $100's of dollars to replace them, I provided a parts list from Mouser.com and the people who had the know how to work on such components/devices I did a nice detailed write up. I did not provide schematics on the public website as I did not want to venture down that road for legal reasons. Parts list (this includes code files that you would likely create) and a pictorial of where the parts go/setup is more than acceptable, no company can go after you for that.

At that point, you are providing a modification that people will install at their own risk. Occasionally people ask me to work on their generator boards and I offer my services including, labor, parts and shipping, all through paypal invoices. I make note that the board is functioning at the time of repair, and offer no warranties of any kind. My internet presence, plethora of forum posts, and youtube videos seem to instill confidence in potential clients. I make sure it is understood I make no guarantees. 98% of the time I am successful at repairing the boards, and if I'm not 100% confident I can repair it I do not take the work. Since much of the know how to repair these boards I made public, I don't get as much work, but I wasn't in it for the money to begin with. Sure its great, but I fulfilled a need I had by repairing my boards and saved myself money. I shared the knowledge with the forum members that helped me. As a result my pay it forward knowledge on the control boards help was greatly received by many Still to this day even.

Here is the thread for those circuit boards as proof of concept.

SCB 83970GS / VRB 84132GS Parts List & Diagrams - SmokStak

What the car insurance companies don't know and can't find out cannot be used against the driver. Far as they know, they don't know shit! Now factory warranties, I'll say this. Arbitrarily adding a device to your car (whatever its function) does NOT constitute a denial of warranty. If such device is investigated to be the cause of any damage to the car (not talking about a vehicle crash btw) then Honda can deny any warranty claim related to that system/part. For such instances if it does cause problems then best to remove the device and say Winnie the Pooh did it and have it fixed!


I hope this puts some of your questions into perspective. Believe me, i share your concerns as well. whatever the application, people seem to care less when there is no money involved. I'd be willing to barter with you though! Knowledge, home brew beer, assembly assistance with the prototype, because I'm 100% committed to having your prototype to test out on my 6MT!:wiggle:

Thank you for the insightful response! I am absolutely working towards the goal of informing the public about the technology in the car systems and the technology I am developing within that system. It's the whole reason I am using Github to post all of my code and my discoveries! This is the perfect project where open source is the way to go - for many of the reasons you mentioned, as well as furthering the pursuit of knowledge in a general sense.

I asked pointed questions about selling these devices because I make the assumption that the market for this sort of thing is divided:

1. The tinkerers who do not mind soldering some wires and writing a few lines of C, and who are interested in improving or changing the functionality of a device
2. The people who want the service or ability that the device provides, but aren't interested in the technical side of things (I'll call it the plug-and-play crowd)

I imagine most people interested in this are in the latter group.

My plan is to make some sort of circuit board with connectors and interface circuitry, which the user can populate with a processor which is commercially available (much like the Arduino), or could come prepopulated with a preprogrammed processor which the user does not have to "play" with and just works. To me this looks like two versions of the board - a "developer" edition, and a "practical" edition. The developer edition could use through-hole parts so you could easily solder one up in your garage, and the practical version would be made a small as possible and maybe come with a case of some sort (at least some sort of protection for installation).

If people are technically savvy enough to make one given the materials I have provided, great! I have no problem releasing all of the data one would need to make one over the weekend. In fact, I would love it if people did this! It's a great learning opportunity. For the second case, I'd happily solder some up for people if they want one that "just works", and provide it for the cost of parts plus labor, much as you do.

Maybe I should only target the technical market - I don't really know. I need to do some more thinking on it, but it seems like a logical place to start at least!

You are very welcome! I think the technical market is a perfect start. You will find that with open source, others contributing to the development will refine your initial ideas even further such as smaller package, pre-made code packets, hell who knows maybe even pre-made wire harnesses but that's a stretch! I think its safe to say most of the forum members are in the technical group too.

IMHO, don't bother catering to the "plug and play" crowd, at least at first. They can easily find a friend who is of the technical crowd to build them the device for some sort of compensation. Your contribution will be a perfect learning opportunity yes! Necessity is the mother of invention and innovation.

You know you're totally right. I'm thinking too far out there...we'll call it a symptom of working in the real engineering field. Always thinking about the product!

In my day job of Supply Chain Logistics Manager and IT (computer systems have to handle that business piece with some serious integration/functionality) we call that "juggling many balls" or "looking at the problem from multiple angles." Looking at the big picture knowing your target audience is also the best advice when deploying something that is not the inherent of the person's skill set. Making something user friendly is not an easy task. Lots of details to make minimum input result in maximum output to carry out a task.

Even I suffer from the same OCD meticulous over-detailed nature of engineering my business space. I think many would prefer the "K-I-S-S" philosophy, but sometimes that's difficult for those who have to track every detail because its our job.

"K-I-S-S" = Keep It Simple Stupid:wiggle::rotfl:

@Ducktapemaster:
I am wondering about aspect ratio on the display. This is controlled completely by the iPhone, of course, so I suspect all we will be able to see on the home screen and apps that don't support landscape will be the quite small portrait screen--which is too small. I know that there is an app to turn everything into landscape, but I think it is only for iPhones that are jailbroken. Is there a solution for non-jailbroken phones?
A second question, will your solution also allow access to other features in the headunit that are presently locked out when in motion? I am especially interested in being able to adjust the bass and treble while driving. Why they locked these out is a mystery to me.
Thanks for all your work on this project. If there is anything you need, let us know. It sounds like you have a number of techie friends here. I was an electronic technician for years and ran a 3rd-party Mac motherboard repair facility for 5 years, so I am skilled at repair and assembly--and source parts from the grey market.
I agree that the kit approach is the best strategy for avoiding legal problems. Others have gone this direction, and it seems to provide the needed protection.

Random thing to point out, but my bass and treble adjustments are definitely not locked out while driving (adjusted them constantly going to and from Florida, depending on whether we were watching a movie or listening to music). What model is yours? Mine's a EX 6-speed.

Now I'm mystified. I checked, and yes indeed I can adjust bass and treble. But I am almost sure that I couldn't do so while driving at some point in the past. I think I checked it more than once. My mind must be slipping.:ohnoes: In any case, thanks for making me check again. I'm happy the feature works while driving since I do use the tone controls frequently.

On page 216 there is a settings adjustment for aspect ratio adjustment I believe should help. I know my Android Note 4 will change the HDMI mirror based on phone orientation portrait or landscape. a bit annoying but disabling the screen rotation option prevents this from happening.

Correction
 

In my question about "aspect ratio," I used the term incorrectly. I was asking about screen orientation, a related idea. iPhones, other than the iPhone 6+, cannot display the home screen in landscape orientation, only in portrait. After doing further reading, I now know that this cannot be overcome without jailbreaking the phone. The fixed portrait mode for the home screen is a programming decision by Apple, not a hardware limitation. What this means for use in the Fit is that the home screen will appear on the car's head unit in portrait, and it is too small to see well. Many apps have landscape capability, so they will fill the screen. I think Google maps does, but I don't recall at the moment. For an app to to truly useful in the Fit, it will need to have a landscape orientation mode. Since the touch screen in the Fit cannot communicate with the iPhone, I suppose the fact that the iPhone's home screen is locked in portrait doesn't really matter much. Home screen is of little interest. So the limitation is only a minor frustration.

Ahh that makes sense. Yeah a minor annoyance for sure, but can be worked around.

Unfortunately the HDMI input isn't perfect, even when it is working all the time. The resolution from my iPhone is a little weird, and the colors seem off for some reason (although it could be due to the image scaling going on). This is one of the topics I'm interested in working on later on. If anyone is interested, I think that the resolution of the display is 800x480 (WVGA), which is a 5:3 aspect ratio.

Also, I did some more testing with my prototype last night and I was able to disable the speed-lockout of the features on the head unit. I had to modify another CAN data frame to do so. Unfortunately, I believe this will disable the speed-sensitive volume control of the unit, but I'd say that's a minor inconvenience.

Interestingly enough, if I only modify the CAN frame with the shifter position so that the car thinks its in park permanently, HDMI is still disabled if the car is moving at any speed! Works great in the driveway though :D. This is what motivated me to change the speed value. Once I did that, everything works as expected - HDMI and all of the features are enabled while driving!

Next week I am going to get another one-day subscription to the Honda service website and look into the wiring differences between the models. If it's easy, I want this device to work on any of them! I think I will have a problem with the Navi models however, since the nav system requires the speed input to calculate the car's position. I doubt that's much of a problem since we want this for Google Maps, right??

You can adjust the HDMI color matching within the diagnostics menu. I dont remember exactly where its located, but I shall make a video how to get to it. Quite simple really.

No love loss here for that! I dont need something to raise my volume at highway speeds, i do that myself already!

BOOYA!

Agreed!!! its most certainly an inferior product.


On a side note, curious, in your travels with the B-CAN and F-CAN decoding. Did you find any signal code that would somehow tell the ECM to shut down? Disable the starter, etc? I've heard big brother has used the GPS receiver to send such commands to disable vehicles if you are late on your car payments.

Would it not be possible to take the data coming in and create a relay that would enable the stock back-up camera and lane watch on an aftermarket head units?
Seems like a device like that would have a wider appeal and there wouldn't be the worry of legal ramifications.

Hi guys, I think there has been a wiring kit developed so that we can use hdmi and usb video while driving. People have already been posting videos of them using iPhone mirroring and using waze while driving..

Easier said than done. Both the cameras are tied to the B-CAN of the car. what you suggest requires a great deal of programing to interface an aftermarket HU with the stock OEM CANBUS network. Ideally you would need to directly connect the backup and lanewatch camera to the headunit for it to accept input based on the reverse light signal and right turn signal. Lets not forget that the dynamic backup guidelines are operated by a steering angle sensor connected to the B-CAN processed by the control modules.

You have any examples? I've searched and found nothing here in the US.

Hey everyone, time for me to come out of the shadows and say hello. I've been helping ductapemaster on figuring some of the CAN stuff out behind the scenes via email and working another software based path of solving this problem. I'm slowly working multiple other attacks avenues here:
1. Modifying the firmware (probably not very easy at all), I'm not even sure if I can get it at this point without risking bricking the HU.
2. Replicating a mirrorlink connection by looking how a valid app does it (I have a decent plan and some small initial progress on this method).
3. Understanding the hondalink app unlock code and using this with other inputs. (I have a plan for this, but buying everything to try it will cost $200+ so I haven't wanted to go there).

I'm looking for people who
- can help me acquire the HU firmware
- specialize in Android app coding and security (especially if you have worked with MirrorLink)
- have the hardware necessary to sniff bluetooth connections

If this is you, please contact me on twitter @JHub908 or by private message on the board here.

My electronics background is limited in coding, though I understand a lot of it.(C++, SQL, etc) All my tools are oriented towards SMD rework and diagnostic. Through hole components too.

Your Item#3 I know you are trying to avoid due to the cost, however, what i can do is make a donation to the cause. I could pledge $20 via Paypal to work towards it. If we get a few other people to contribute I'm sure that could help offset the cost for you. The hope and expectation would be to see some sort of result from the research (positive or negative) would be seen. I almost lose $20 in poker every weekend with the guys so I'll chock it up to a one time expense for a good cause that I'd like to see to completion, at the very least some vigorous development/discovery on.

I appreciate the offers for money, but at this point since I have absolutely no idea what to expect out I don't think I want to go that way yet. If at some point in the future I'm more certain that cash is the only thing holding me back perhaps I'd investigate the option.

Some clarification, for the Hondalink method, I would need...

- Hardware to sniff Bluetooth connections ($120) - I'm ok buying this since I can use it for other projects later.
- An Apple lightning to HDMI adapter ($50) - Great if it works, perhaps not wasted money if I ultimately go with the custom hardware route instead.
- And an app that shows something on the screen that uses Hondalink I can reverse engineer traffic for.

The app is my holdup, and I have a question on this, will the aha radio app give me what I need here? Or will I need to buy that garbage $60 navigation app? I haven't been able to test it since I haven't bought the HDMI adapter yet.

Another question, how sure are we that bluetooth is involved in "unlocking" the screen for the Hondalink apps, is it possible that it's done over USB? If so, I would need different hardware for analyzing that and don't want to make an expensive mistake.

Sounds fair!


AHA I don't have any experience with. I'd imagine it operates similar to Pandora. there is no HDMI functionality with either of these programs. You may wind up having to purchase the shitty HondaLink navi app. :-(

Ducktapemaster should hopefully be able to answer this. My initial assumption would be yes. There is no mention of the USB being required for the navi app to work. There is a Hondalink launcher app that generates the authentication (assuming via bluetooth) and unlocks the HDMI input on the HU.

Let me know if I can be of further help!

Bass

Hello Ductapemaster, everyone,
I've got the 2015 CR-V with navigation. My car doesn't care about the parking brake or the shifter. It's lockout is strictly speed based. And that is through the CAN bus. I experimented one day. I don't have an accurate wiring diagram, so I pulled out Head Unit connectors one at a time. When I pulled out what must have been the CAN connector, I got locked out at any speed, parked or not. The GPS antenna was still plugged in and functioning. So I know the lockout is CAN based and not GPS. The Honda Nav is not the nicest, but if I can have my wife use the GPS while I drive I guess I'd get by. Honda says drivers can use the voice commands while driving, but they are awful! The voice menu is overly cumbersome and it often doesn't understand me. I had been using a Garmin and with it I can use either direct input or voice commands. And the Garmin voice system is fantastic! Anyhow, I've got some experience with Arduinos. I'd think your microprocessor solution would be the way to go. It would unlock all the functions and preserve some of the nicer features. I'm willing to support the effort. If you need some test data on a car with Nav I can help. If you are willing to share your circuit design and code I can buy, build and test it on my car.
Thanks,

This looks awesome! I have some concerns about this method, maybe you could address them.

It looks as though the chip you are installing reads ALL the CAN bus data and passes everything through, only changing the vehicle speed items. What would happen if this chip malfunctioned/died and stopped passing that info through? Would the head unit stop receiving all the bus info, and what would that mean for normal operation of the car?

Thanks in advance for your reply and your work on this; I would LOVE to be able to have useful apps displayed on the screen.

Hey guys, I live! Sorry for being quiet for so long - I was overseas for 4 weeks on business.

The good news is I have ordered some custom PCBs for my prototype hardware! They should be arriving in just over a week. I appreciate all of the interest in this project and I can't wait to start putting things together in a more useful form for everyone.

Yes, this is possible. I may look into this in the future if there is enough interest, but for now it would require a lot more custom hardware as there are multiple communication lines for the cameras (not just BCAN).

If this chip 'dies' and stops passing data, little is lost. You can operate the car normally with no head unit (I drove around a lot like this). Obviously there is the possibility of a total failure, like shorting the BCAN lines, which could be more catastrophic. I've actually accidentally done this before and it was weird. The horn started blaring and the car wouldn't unlock with the remote (presumably because the safety system wasn't getting the right signals).

We're playing with things we aren't supposed to touch, so I won't say its without its risks. However, the failure modes should be relatively sane barring some electrical short.

UPDATE: PCBs have been shipped to me as of this morning! I am getting 6 custom boards in. I just ordered all of the parts yesterday, so by mid-next week I should be having an assembly party.

If you look closely, you can see some issues with via sizes and spacing, but I think everything will be OK. I screwed up when I submitted the boards - I forgot to run the design rules check file for the board house, so some things got resized automatically, resulting in the weird spacing and whatnot. Things to fix in V1.1

https://cimg2.ibsrv.net/gimg/www.fit...aea8de062a.png
V1.0 board top

https://cimg1.ibsrv.net/gimg/www.fit...514f92d0fd.png
V1.0 board bottom

Also, on another note, I have some additional thoughts on a "failsafe" for the device, as per the discussion in my post above. I'm going to put a couple miniature relays on the board which, when power is disconnected, will make the device electrically "invisible" to the car. Basically, they will just short the CAN lines and the other two signals across the board and the head unit will be connected directly back to the car.

I think that this will help alleviate some possible failure modes.

Awesomeness!

You're incredible! How can we get in line to purchase a kit?

I'll call "dibs," if thats all it takes! ;)

Sign me up

I'll be putting together a poll to gather interest in the next few weeks, assuming my hardware checkouts go well!

I will need to do some checkouts on other trim levels as well before I start putting together kits. Once I have some pieces of working hardware I will begin to address that.