jumiduss

Hello, this is my first post but after a bit of research I would like some secondary opinions or topics to research to further knowledge in completing this project. The purpose of this post is for constructive advice and if I embark, possibly allow others to learn from what I plan to make.

Intro:

From my limited car audio experience but extensive desktop audio experience, the upgraded audio and everything sounds terrible. My comparison is coming from a '09 Rav 4 which after replacing the stock unit with a pioneer unit the sound quality increased dramatically. I doubt the stock speakers are worse than an '09 Rav 4 which leads me to assume that the head unit is sending out a terrible signal. Highs are unclear, bass isn't pronounced enough for my liking. Things that could be changed by buying a new head unit, except this is not possible with the NAV version as I've read throughout product descriptions and forum posts here.

Because of these problems I wanted to create my own system that is different from what I have right now. I want my car to work and look modern, while keeping the great engine and body. Currently I'm dissatisfied with the navigation system. It's clunky, unresponsive, defective, and produces, in my assumed guess, the poor audio quality I'm experiencing.

Wants:

• Better Bluetooth pairing / self streaming capabilities (like a tablet)
• Steering wheel controls
• Backup camera with predictive steering
• Physical air conditioning buttons.
• A screen setup similar to the mock Tesla screen available for our car
• Screen layout where top half is music information + A/C info, bottom half is sys-info like the torque app
• Use all speakers all the time instead of only when using DVDs

Ideas:

1: Remove All Stock

Taking out all stock modules, integrating with the car using a linux machine / android tablet through CAN bus. Currently very limited to this for lack of CAN bus knowledge, but have been able to control blinkers through the OBD2 port and working on controlling AC through this now.

2. Keep AV CU and Build Around It

Keeping AV CU (audio video control unit) and strip back wire harnesses to put into new switches that I can route to a different spots. Other things I would like to control I will send from the tablet / PC to the AV CU. Take the AV CU communication signal to a tablet / PC to display backup camera and other uses.

3. Bypass Current Audio

I haven't researched this as much, but this would include installing something behind dash which can accept Bluetooth signal and be controlled with the NAV unit. This could be possible through splicing the steering switch cable and using the purely audio to control a Bluetooth module that sends the signal to the amp.

Tools:

• Experience using Arduino IDE and boards for switch integration into the system
• Currently learning and testing CAN bus signals
• CAN bus reader and transmitter for mid and low can data signal which should be fine for secondary car modules
• 3D printer for making new face molding after creating a 3D model using photogrammetry on current dash for dimensions
• Practicing creating circuit boards to print
• Time

Road Blocks:

1: Remove All Stock

Car is overpowering my signals to control AC (which talks between the AV CU, TCM, and M&A (unified meter and A/C amp)) which means codes sent either don't get accepted or once accepted get overpowered by an old setting not changed in one of the units / modules. This method is going to be the hardest to troubleshoot and get all of the units to communicate nicely with each other. The Sonar Control Unit, Antennas, Bose Amp, Mic, Review Camera, switches, position sensor, are tied to this system. In spite of these issues, this system would give a massive amount of space compared to keeping the AV CU.

2: Keep AV CU and Build Around It

This seems like the best of both worlds. I can have a big screen while not fussing with having to program into the CAN bus, and also write small programs to interpret signals from a thousand modules. This method has the ability to fill all requirements stated before.

Currently the problem with this method is finding the space and coming up with fabrication ideas. The AV CU is not small and the monitor / tablet needs a proper amount of space. Since the new trim is going to have to clip into the old mounts I'm not sure how stable the monitor / tablet would be without tearing the new trim out. I don't think redoing switches would take more than a day or so. The second problem I have is figuring out how to trigger the amp on signal and the mode signal change, which could be done the same as method 3.

3. Bypass Current Audio

The only problems with this system would be not filling the wants stated in the beginning. This would only fix audio and provide the least amount of maintenance, but missing many features.

Process:

I believe that option 2 is the best in this case, supplying the easiest method while keeping all wants. This is my plan about creating the system:

1. Having the stock image transferred: https://www.myg37.com/forums/audio-v...nexus-7-a.html
2. Reverse engineering AC switch through a multimeter and then modifying AC switch harness to secondary switch board that meets design requirements for new Monitor / tablet
3. Reverse engineering Steering Wheel switch with multimeter, and interfacing that with the tablet / PC through a motion joy adapter / arduino board.
4. Use Bluetooth controller/switch with receiver hooked up to AV CU to navigate stock menu
5. Print new trim piece with CR-10 3D printer with proper strength plastic. Then prepare the trim for paint / wrap. Specifications for trim piece is for snug fit around tablet with ability to remove tablet when needed.
6. Print new switch for AC that clips into trim piece
7. Set tablet for startup / shutdown with ignition like here
   https://www.youtube.com/watch?v=KXfWYDw_rD8&t=344s
8. Set pc bios to restart on receiving power
9. Research more on mode select for Bose amp
10. Research more on displaying AC info on screen / looking at stock screen, which could be done through
    "
    "
    ScanTool OBDLink LX"+
11. Aux out to Bose amp and use DAC if signal is not clean enough from source.

Conclusion:

I created this post hoping to receive some input from other experienced modifiers for a direction to look towards or possible inspiration for my project. I hopefully will be able to start on this project soon and post updates as it goes on. If you have any advice or comments I would love a second opinion outside of it's going to be a lot of work. I'm not afraid of work . I'm afraid of destroying the car for something that doesn't operate as intended.

Thanks for reading and look forward to hearing from you.

Landshark

theTesla screen would solve *most* of your problems.

as far as sound quality, adding a powered sub is #1. i use a sealed enclosure because for what i listen to - i want tight and accurate bass. you may want ported or bandpass depending on your music tastes.

i also hated the Bose system, but after trying many devices and apps (iPod direct, Android on Bluetooth), i found that a rooted Android phone running Viper4Android sounds best.
my current phone can't be rooted, but using the Jet Audio music player with its 20-band EQ and various DSP add-ons, the Bose system sounds pretty good to me once its tweaked.

Landshark

also. i have a Nexus 7 (2013), and its showing its age. probably not a great idea to spend all that time and money to put a 6 year old tablet in the car.

mattisz

Hey Jumiduss, believe it or not I am currently working on a similar project that I started about a week ago. While this post probably wont answer all of your questions, here's some information I've found out.

CANbus
Trying to interface with the canbus has been a serious pain. I can reverse most of the signals through trial and error but sending commands has been a problem. My plan, as of now, is to read information from the canbus and display it on my Nexus 7. The most important thing for me here is the climate control settings. As the car has physical dials/buttons to control the temperature and fan speed, I don't necessarily need to be able to control them remotely through the canbus (although it would be nice so let me know if you figure that out), however, I would like to display the current settings on my tablet which is reasonably doable. My theory is that because I'm tapping the canbus through the OBDII port, there might be some logic preventing me from controlling the AC unit. Eventually, I'm going to tap the canbus at the A/V control unit and see if I make any progress there.

Bypass Audio
I'm struggling a bit with this one myself as it would clearly be the easiest/least time consuming route but I have other goals for my project as well. I may still go down this road but it would be in addition to what I'm planning, not instead of. The Bose amp is located under the rear parcel shelf, I believe you can access it by pulling down the trunk liner but I haven't gotten there quite yet. This forum is filled with good advice on sound processors and other options if this is the route you choose to take to increase the performance of your stock system.

Keeping the Stock A/V CU and Building Around It
Alright, so it looks like we both arrived at the same conclusion, this is the route I am planning to take. This is not going to be easy for a bunch of different reasons but I think it's probably the best option because I would like to avoid hacking the car to bits. Dealbreakers for me are the backup camera and the A/V CU output for diagnostic reasons. Additionally, I would like this install to look as stock as possible to avoid breakins and making the car more difficult to sell when the time eventually comes.

Tablet Choice:
I'm not sure if you have one or if you just linked to a Nexus 7 video but surprisingly, this is still one of the best tablets for the job. It supports USB OTG so you can plug in peripherals, you can easily mod it to remove the battery and run off you vehicle's power, it's 7" just like the stock display so very minimal work needs to be done in terms of fabrication, and it has fantastic display resolution. If you're looking for a bigger screen, I don't have any great recommendations for you but some people like the Tesla style displays.

Stock Display:
If we had an older G or the non-nav version, hijacking the feed going to the stock display would be a cake walk. I was originally inspired for this project by chrismitch's post: https://www.myg37.com/forums/audio-v...nexus-7-a.html
Unfortunately, our cars don't use the old RGBS format to send data from the A/V CU to the screen. The newer G's use a proprietary format made by SONY called GVIF. Basically, our A/V CU sends the data to the screen's control board over a single twisted wire pair. The display board has a CXB1458R receiver chip on it that takes the data from that pair and deserializes it to 24-bit RGB. The display board also receives data from the backup camera, and the DVD player and uses a Cyclone II FPGA to determine which signals to send to the LCD. The connector from the display board to the LCD panel is a 60 pin FFC cable. I'm waiting on some parts to arrive to try to decode which of those 60 pins does what. Sadly, I don't own an oscilloscope or a logic analyzer and my G is my daily driver which means my testing will have to be done outside of my car on a fairly limited basis. I find it difficult to believe that all 60 pins are being used on that connector. Counting traces to the pins, I only see 34 connections but there could be more on the underside of the board. My hope is that this is just a 24-bit RGB TTL connector with some extra pins for stuff I don't plan on needing. While I could solder to the CXB1458R directly and steal the RGB data from there, the leads are very small and I would prefer a more elegant solution. Additionally, doing so would only give me the image data from the A/V CU, not the backup camera or the DVD drive (not that I have ever used that). The display in my 2011x w/ Nav is a Toshiba LTA070B2H0F. Unfortunately, there is no publicly available datasheet for the display so there really isn't much possibility of getting a pinout of the 60 pin connector, it's going to have to be reverse engineered.

Parts List
Advantec PCM-261T-A0A1E ($80ish): This board takes 24-bit RGB data as an input and outputs to DVI. It's the only board I've found that can do this. DVI and HDMI use the same standard minus the audio and HDCP so converting DVI to HDMI is trivial if you need to.

Inogeni DVI/USB ($350): I happened to have one of these lying around so I'm planning to make use of it. I probably wouldn't recommend something this expensive for this project but it's what I had. Essentially, it's a driverless DVI capture card. So I can take the output of the PCM-261T and view it on my Nexus 7 through a webcam app like in the guide I posted above. I'm sure any driverless DVI/HDMI capture card will be fine. The tablet just needs to view it as a webcam.

60 pin FFC breakout board(<$10): These can be purchased on AliExpress for a few bucks. The FFC is too delicate and the leads are too small to try to mess with directly. One side of the board is a 60 pin FFC connector (.5mm pitch) that I will connect to the display board, the other side is two rows of 30 pins each at standard 2.54mm pitch. I'm going to solder on a header to this board so I can make a cable that goes from the board to the PCM-261T once I know what the pins do.

Misc: Some extra 60 pin FFC cables because the oem one is permanently attached to the LCD. A Hirose DF-13-40DS cable housing so I can plug into the header on the PCM-261T. A Hirose HIF-3BB-60D-2.54C housing for the other end of my cable that will plug into the breakout board. And an A1-60PA-2.54DS header that I will solder into the breakout board. The DF13 has 1.25mm pitch pins which require a special tool to crimp that costs hundreds of dollars, so I found some precrimped wire on AliExpress that has DF13 crimps on one side and standard 2.54mm crimps on the other side. It was $1 for 12x6" wires so I bought a bunch to use for testing.

Final Thoughts
So that was probably more information than you were asking for but hopefully some of it is helpful to you. I'm still waiting on my AliExpress orders so it will probably be a few weeks before I really get to do any testing on this but definitely keep me posted on your results. My plan is to purchase a Carplay/Android Auto dongle for my Nexus 7 so that I can use my phone's data for Navigation with Google Maps and for listening to music. Basically, I'm going to use the Nexus 7 as a head unit. The problem I'm facing is interfacing with the car's audio. I don't see a reason to use a DAC to convert the audio from the Nexus 7 to analog, when there is a digital input via the USB port in the center console. Unfortunately, that input only works with iOS so I'm going to try out the Wirelinq by Grom Audio and hope that it works well with the Nexus 7. If not, I'll probably just tap into the XM radio feed like in this guide: https://www.myg37.com/forums/audio-v...io-i-know.html and use FiiO E17K to get the audio from the Nexus 7 to the car's speakers. I'd like to avoid this solution if possible but it's a decent last resort. Ultimately, it sounds like we're both traveling down a similar road so if you have any questions I'm subbed to this thread. Try to post any updates as they may benefit both of us/others in the community.

P.S. Sorry for the thread hijack, just trying to help.

jumiduss

Hey, Thanks for your reply!

Looking more at the project I'm going to be getting a tablet that is newer that supports the otg cable and possibly just run a 2 screen setup with a dedicated music tablet installed in the dash.

From reviews I read on here the Tesla screen isn't very good because of longevity and customer service issues of wrong cables and such. Seems like a lot of money to waste in my opinion, to each their own though. I will keep your suggestion in mind if I end up using a tablet.

I was confused at first about the subwoofer comment because I thought the upgraded system already contained one on the upper deck of the trunk, but turns out it's a woofer like the door speakers. Currently that doesn't even work so I'm very confused about this whole situation haha.

jumiduss

Hey mattisz!
This is EXACTLY the kind of information I was looking for so thank you!

CANbus
In reference to CAN bus network. As far as I can see the network is extremely hard to work on. I only started working on it from about a week ago and was quickly dissuaded because of the amount of work that needs to go into it. When messing with the AC controls on 53D? I couldn't get a signal through to the module. My thinking is that the two modules are talking so much back and forth that a brute force method is needed to override the system. I'm personally no longer as ballsy with this because of the scare I just had where I broke the fuse for the gauge cluster I just had all of that replaced which was a $1500 dealer repair so I don't want to mess that up LOL. If you need help mapping things, there's some sources I found on Nissan cars that seem to have the same, if not exactly the same, hex values as the G37. I had an module called "CANable" (which is a pain to try to google tutorials on pun words) which was about $50 shipped. Turns out it only does 125kb and 250kb writes, so this could be the problems I had. Other methods are going to cost at least double. I couldn't find enough detailed information so I don't find it lucrative.

Bypass Audio
I can see this is where we differ in our projects, so I'd love it if you kept posting here so we can possibly fill in the gaps of each others builds. I found out today that my rear woofer isn't even turning on for any mode, which could explain why quality was so bad. I found a post listing speakers from "infinity" that are priced around $100 per each. This could be a worthwhile investment but I'm still more concerned about a custom exhaust than the audio

I pulled out the trunk liner today and there's literally like 6 buttons you pop out and some velcro on the back side and that's it. You'll immediately see the amp and woofer on the roof of the trunk. According to the diagrams in the FSM the amp powers the woofer but I couldn't see the connection. After doing some sloppy testing of unplugging harnesses on the radio to see which one stopped the signal to the amp, I think I found the power ribbon which if you're looking on the back is about 10 ish wires on the bottom right side. This possibly has the audio connection in it because I thought I tried every other connection except that one, but it's just an assumption.

If you're interested in working on the audio here's a link and corresponding info.
https://forums.nicoclub.com/g37-subw...p-t525470.html
http://www.nicoclub.com/FSM/G37/Sedan/2012/AV.pdf go to page 365 for nav with bose diagram. This might even help with your video problem. It looks like 2 pins on the lcd are for the backup camera so that might help.

Ideas:
This project is over ambitious and needs to be scaled back for me. I want the benefits of a tablet while keeping everything else the same.
Audio

1. steal audio switches from steering wheel and remove audio switch panel. On controls going to tablet for audio, connect them to a bluetooth module and set them up as a controller for the tablet. For me I only want spotify for music so I couldn't care less about any radio features.
2. Run a cord from the tablet to the new amplifier in the back through cord channel. https://www.carid.com/lanzar/heritag...pn-htg888.html (I'm not positive this will work but it's an 8 channel amp which might not have the right resistance)
3. Use wiring diagram to connect proper speakers from harness to the new amp

This should solve the audio problem.
Dash

1. I now see no reason to remove the screen. You could keep stock screen right where it is, possibly push it out to make it flush with the dash, and then add the tablet right underneath it. Running a dual screen setup which would cut out the need to mess around with any porting. Once again there is a problem of moving the controls around to fit on the new dash.
2. I found out today that the two important buttons for diagnostics are the up arrow on the dial, and the back button. This puts it into diagnostic mode for fault testing buttons. Otherwise as stated in the original post you can just make a new switch panel. I don't know how nice it would look, but it would be a heck of a lot easier. Like I said before my plan was to remake the dash with a 3D printer, so I could make proper placement for these two. I'm not sure how much you actually want to change your dash around so this method might not be right for you, but it is an idea.
3. The problem that you can run into is with displaying the sys info. Now like I mentioned in the origional post, there is that bluetooth adapter which might be able to give enough information to satisfy me / you. Not extremely expensive, but there is a joy in getting that information yourself. Then you can purchase a tablet with screen split, one for music / nav and one for sys info. From what I understand be all set. There would be no reason to use an OTG cable. Controls are bluetooth. Audio exists as an aux (unless you use a real DAC for digital to audio). Power is controlled through voltage signal through usb port.

Parts:
Tablet with android 7.0 + that supports split screen. ~ $80.00 - $200.00
Aux cable long enough to stretch from dash to trunk. ~ $20 for wire if you make connectors yourself.
2 Arduino Uno (with bluetooth module). One for stock screen one for steering wheel controls . ~ $40.00
1, 8 Channel amp from link above. ~ $170.00
Filament for 3D printer. ~ $20.00
Assorted power cords for boards. ~ $10.00
Total ~ $350.00 - $450.00
Conclusion
I hope I'm not missing the target too much. In my opinion this seems much more reasonable, and it should be able to finish with in a couple months. Feel free to target my post for possible faults so I can tweak my plan.

I guess my question is what do you wan the end goal of your setup to be? If you wanted a cheap setup you could have a tablet holder on the hood and feed a USB through the top speaker Most data will feed through the usb except audio, so 2 cables and a removable tablet. If you split the audio controls to a arduino then no hacking on the ribbon cables. No need to replace stock screen if tablet is remote. Secondary idea is routing out a little area in front of current screen and installing tablet in front of that which looks clean and has the ability to look at the stock screen by removing dash. Anyway I'm a little tired so these aren't mind blowing ideas haha.

Back up camera hookup using similar idea as this: .
Nissan CAN bus codes which should be similar to Infiniti (from the logged values I got) https://github.com/Knio/carhack/blob...issan.markdown

Good luck on your project and feel free to co author this thread with me.

jpowersjr2

iTrader: (1)

Subscribed, this is going to be good.

Landshark

check the Facebook group - lots of info there. it can get a little complicated, but i think the issues have been ironed out. it seems if you purchase from Phoenix and not a random Chinese site, you may do better. i just bought a Q60 RS400, and it seems the unit has been out for that model longer and there is less complication. i may buy one for it in the future.

not sure about the sedan, but the coupe has 2 6x9 "subwoofers" that get 30w of power. i think the sedan has one larger "subwoofer" LOL pretty much a joke.

Absinthe

I applaud your ambition but one of your initial premises is incorrect. The Infinity head unit puts out extremely clean and balanced audio. Its the Bose processing after the head unit is what renders the audio to crap. The speakers are so-so but are untimately designed to work with the amps and processor so adding aftermarket processors and amps will illuminate the shortcomings of the individual drivers.

miatawnt2b

I am super excited to see your progress and if the PCM-261T-A0A1E can decode the GVIF signal from the head unit. With my QX56, I am only really concerned with the HVAC data that is displayed on the screen. It's pretty low res, so even if I can convert the GVIF to a composite signal I'd be really happy. In fact, I'd probably rather have composite because all of the cheap android head units have several composite inputs these days.
-J