# Nexus 7 tablet install - 08 Lexus IS250



## simplicityinsound (Feb 2, 2007)

This is a pretty cool case of a project evolving with technology.

two years ago, i did a pretty simple IS250 SQ build:

http://www.diymobileaudio.com/forum...le-sq-build-08-lexus-is250-mosconi-morel.html

as with any of the 2gen IS builds, this one utilized the stock HU and amp as a signal source.

fast forward to present, the customer contacted us with an idea he had, that is to integrate a nexus 7 tablet into the dash, along with a single din sony headunit (with its app remote feature) so he would have two much improved signal sources along with all the added benefits of having a tablet.

this design actually went through several phases, originally, the idea was to have the headunit behind the tablet, but then a discovery was made that for the android app remote to work, you may have to manually engage something on the sony headunit, at that point, the decision made to have the headunit visible and belowt he tablet, which made for some extra work. but in the end, the funny thing is the customer found some very cool ways to make the steering wheel controls to work with just the tablet, so there is a chance that down the road, the sony radio can be swapped out with something else. 

it was a pretty fun project but involved a LOT of intricate electronic work...lets take a look at the final results first, as you can see its quite a tight fit, the nexus 7 sits snugly in the dash, held in place by an array of 6 magnets and is easily removable. the sony GS610 headunit is belowt he tablet and the entire bezel has been rebuilt and painted silver.














































here is a quick moving showing the tablet in action:






with the new signal sources, i rewired the amp rack and removed the stock amp sepaker wires, but other than that, the trunk and the rest of the install looks completely the same...lets focus on some of the build pics of the car.

here you see the stock dash taken fully apart. note that the HVAC display and the stock headunit display is on a common circuit board:



















then the main switch panel was cut in two, so only the HVAC switches remained, to make room for the tablet:



















note that the two displays are raised quite a bit off the board, so in order to gain enough room for the tablet mount, joey then ahead and removed the display for the now useless oem headunit:



















now you see how there is enough room infront of the circuit board to fit the tablet:










next the switches on the bottom dash bezel was removed andt he two pieces fused together using CA glue reinforced with strips of ABS:




























here you see the new tablet holder with its 6 embedded neodymium magnets about to be bonded to the dash bezel. note little lip at the top that follows the contours of the stock dash bezel...and just how little room there is overall to fit everything 










next comes the REAL tricky part. the one thing that had to be retained somewhere in the car was the hazard switch and passenger air bag light. that panel was relocated into the glovebox but it had to be still connected to the main circuit board.

it its original format, the two are linked with a short ribbon cable, which now had to be somehow made to be about 3 ft long. so what joey did was to carefully scrape the ribbon cable to expose the traces:










and then carefully soldered wires to each of those traces. note how the wires are soldered with the bare end facing each other. this allowed joey to carefully cut the ribbon cable in half and now he has an extension with two ribbon ends.

once he verified that all the leads are connected with no shorting, he poured ca glue over the connection to form solid protective layer:










here you see the tablet mount being molded into the dash, which basically was a lot of sanding and filler work:










one last thing that had to happen was that the main board of the stock headunit had to remain in the car to run the hvac functions, so the stock headunit was stripped bare down to only the main circuit board, and joey fabricate a mounting plate and adapted it to fit the oem plastic brackets. this relocated the circuit board vertically all the way in the back of the dash:



















and finally, the new dash bezel finished and painted and at htis point, everything was bolted back in the car










so...phew, man i got a headache just looking at those pics, definitely one of the more interesting projects. 

Cheers,

Bing


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## thundeer (Mar 19, 2012)

As the customer, I just wanted to chime in and provide some additional details on both the hardware install and also the software setup  

First of all, I just wanted to say a big thank you to Bing and Joey, especially Joey who did all of the amazing fabrication work. Joey was working under a time constraint because I needed the car back on a certain date and he worked late hours just to get it all done on time. On top of that I had some very specific requests for the build design that he had to incorporate. Most of you are already familiar with the work these guys do but just to reiterate, they do fantastic, professional work to satisfy their customer’s needs. I’ve been back once already and if I come up with other ideas to improve on the car down the road, I would come back again. 

There have been many documented installs of tablets into cars, but not much on this specific tablet (Android Nexus 7, 2nd generation 2013 model) into this specific car, a Lexus IS250, non-navigation, non-ML (Mark Levinson) system. If you just want a quick and dirty summary of some relevant info, I have a google document available (https://docs.google.com/document/d/1LvlOxhqeOoILWKGAMPaJV7d8SVRpAFg3o8JoT4sIFc8/edit?usp=sharing) with a list and links to all the “behind-the-scenes” parts that were necessary to make it all work, the tablet software and apps used, as well as some wiring details specific to this vehicle. If you are interested in doing this for your own vehicle, I hope this will help  It took me hours and hours of online research and scraping together information from forum posts, wiring diagrams, and also our own trial and error before coming up with a 100% working tablet install that makes no sacrifices with regards to OEM functionality. 

As Bing mentioned, the original idea was similar to previous tablet installs (see their previous work here: http://www.diymobileaudio.com/forum...50907-ipad-mini-dash-1999-toyota-4runner.html) but with an android tablet instead. As some of you may know, android systems always seem to require just a little bit more complexity that prevents an easy, smooth integration, but that is the price to be paid for the enormous capacity for customization. In this case, before the install, I discovered that the android system can connect to the Sony headunit wirelessly via bluetooth, unlike the iPad which requires a USB cable. However, to “start” the AppRemote pairing, a button on the headunit must be pressed. Therefore, the headunit could not be hidden behind the tablet, and we decided to figure out a layout that would work.

The tablet was initially supposed to replace the bottom half of the OEM center console, similar to how other shops have installed double-DIN systems in that space, with the headunit tucked behind (example: http://www.diymobileaudio.com/forum...llery/104440-2008-lexus-is250-double-din.html). Now that I wanted the headunit exposed, I had to find space for both units. I realized that if I had a standalone headunit replacing the OEM radio, 75% of the center console buttons and displays were no longer necessary, as long as I kept the circuit board behind the OEM radio/CD changer (bottom half of the console), a requirement for non-nav, non-ML systems (as documented in the build log linked just above). I would also need to relocate the hazard/clock assembly. This would require a lot of cutting (as you can see Joey did ) and even then, Joey barely had enough space to fit in the tablet while keeping it flush with the face of the rest of the console.

Joey’s insane soldering skillz shown in the build log with the ribbon cable allowed us to move the hazard/clock assembly anywhere we liked. Putting it in the glovebox was a good option but required me to reach over and open the glovebox to turn on my flashers. We figured out that the hazard switch could be wired up with a simple on/off switch (see google doc for detailed wiring) and relocated to a panel on the left of the steering wheel, above the gas/trunk buttons (if you look at the previous build log, it is in one of the blank panels next to the bass knob). This allowed us to take the circuit board out of the hazard/clock assembly, and tuck it behind the center console. The car will actually start fine if you disconnect it completely, but the SRS airbag light will turn on, and who knows if the airbag system for the passenger would be disabled permanently. I certainly don’t want to take that risk. Plus, Joey’s exquisite soldering would’ve then gone to waste 

The other thing I wanted to mention specifically: the Joycon series of modules (http://www.rcjoycon.com/ WARNING: their website goes down every other hour it seems, but other websites that sell their products also have their documentation available) has been used in many car PC installations as a way to control Windows PC functions with the OEM steering wheel buttons. What it does is turn the resistive (or in some cars, digital) signal from the OEM steering wheel buttons into a USB keyboard signal that can be recognized by Windows PCs, but also fortunately for us, Android devices. The functionality isn’t perfect, setup has to be done on a PC first before connecting it to the tablet, but in this manner we were able to eliminate the need to access the physical power and volume buttons located on the edge of the tablet, making for a super clean install (the power button functionality is replaced by an on-screen software button/widget). The driver can then control volume, track seek, and even the back/home keys from just the 5 steering wheel buttons. Again, sounding like a broken record but please refer to the google doc linked at the beginning of this post for wiring and setup details. 

One final comment on how the tablet outputs audio: I specifically wanted the tablet output from a USB audio DAC for a cleaner signal. We chose a DAC that does not require a separate power switch or a power supply, so that it turns on automatically when the car is turned on. This also allows us to not require a separate cable connected to the 3.5mm audio output on the tablet, again, a cleaner install. Bluetooth connectivity to the Mosconi 6to8 addon board is also an option, but costs more. 

Finally, some comments on the software setup (details and links to all software/apps are provided in google doc): 

CyanogenMod 11 nightlies (I think I’m currently on a build from early June 2014) was chosen for its USB audio output capability, and all the extra customization it brings to the Nexus 7. Other ROMs may also provide this functionality, up to user preference. 

The kernel by Glitch (r142) was chosen for AC charging, double tap 2 wake, and CAF compatibility (with CM11). Other kernels also provide these functionalities (ElementalX, for example), all up to personal preference. 

Tasker is a MUST for automating functions such as tablet shutdown, Wi-Fi tethering, Tablet Talk connectivity, and anything else you desire. 

Tablet Talk allows me to answer calls, view and answer texts, all from the tablet screen. No need to glance down at my phone to see who is calling or who just texted me. 

The Dashcam app in conjuction with the FEBON UVC grabber card allows for display of a RCA video feed, but it has to be started manually. Automation is theoretically possible, as the Joycon exr can sense voltages on one of its input channels and you could tap into the power for the reverse lights, then convert that into a USB keypress combination, then use an app (such as keyboard helper pro) to automatically launch the dashcam app when that keypress is detected… but it takes me literally 1 second to tap the app on my tablet screen to launch it before I shift into Reverse 

Feel free to contact me via PM or post below if you are attempting a build like this and would like more questions answered. If you are in the SF Bay Area and would like to get this done professionally, contact Bing and Joey (and now Jesse and Julia!) at Simplicity in Sound, best in the business, worth every penny.


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## charliekwin (Apr 22, 2012)

thundeer said:


> ...android systems always seem to require just a little bit more complexity that prevents an easy, smooth integration...


Speaking from personal experience










Nice work.


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## JayinMI (Oct 18, 2008)

Thundeer, this is great info. I've been going back and forth about whether I want to do a tablet or not, and I wanted to go with an Android tablet for the many options in size. But it seemed that I would have to give up many things...then I started leaning toward an iPad mini for simplicity's sake. 

So glad someone went to the trouble of putting together something like this...in case I decide to go that way. Great work. Thanks!

Jay


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## thundeer (Mar 19, 2012)

Does not look like I can edit my post so I am putting this here as an update to the end of my previous post:

CyanogenMod 11 (M7 snapshot build from June 2014, on 4.4.2 base in order to be compatible with Glitch kernel, see below) was chosen for its USB audio output capability, and all the extra customization it brings to the Nexus 7. Other ROMs may also provide this functionality, up to user preference. 

The kernel by Glitch (r142) was chosen for AC charging, double tap 2 wake, and CAF compatibility (with CM11). For some reason, I cannot get OTG charging on startup to work with other kernels such as ElementalX.


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## dlcs500 (Aug 1, 2014)

thundeer said:


> Does not look like I can edit my post so I am putting this here as an update to the end of my previous post:
> 
> CyanogenMod 11 (M7 snapshot build from June 2014, on 4.4.2 base in order to be compatible with Glitch kernel, see below) was chosen for its USB audio output capability, and all the extra customization it brings to the Nexus 7. Other ROMs may also provide this functionality, up to user preference.
> 
> The kernel by Glitch (r142) was chosen for AC charging, double tap 2 wake, and CAF compatibility (with CM11). For some reason, I cannot get OTG charging on startup to work with other kernels such as ElementalX.


Hey man, I PM'd you. I'm really interested in doing this to my 08 lexus IS 350. I already bought the non navigation dash because of this thread to use since I have the stock nav in mine. 

Thanks,
DL


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## thundeer (Mar 19, 2012)

dlcs500 said:


> Hey man, I PM'd you. I'm really interested in doing this to my 08 lexus IS 350. I already bought the non navigation dash because of this thread to use since I have the stock nav in mine.
> 
> Thanks,
> DL


As far as I know (not 100% sure) from my research online, a non-nav dash doesn't plug straight into a nav car, I think one or two of the plugs are different (for the GPS antenna, mic, rearview camera, etc), which you'll see when you open up the dash to compare. I've never seen the back of a nav dash so I can't say for sure what's different, but there have been instances on the internet where people have gone from non-nav to nav, and having to change a few plugs, so I'd assume the reverse is a similar process. I have no experience at all with the process though, so unfortunately I can't help you there. ClubLexus forums are a good place to start searching. Good luck!


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## lexuslove (Oct 2, 2014)

Nice work on the install that looks amazing. I was wondering how much an install like this would cost to have it professionally installed? There is no way in hell I could do that great of a job on the build quality. I have an 08 lexus is 350.

Thanks!


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## theazndan (Jun 14, 2015)

Amazing! What is the function of the Sony nfc radio? I noticed that the steering wheels are controlled with Joycon to tablet via OTG cable, very nice touch. Main question really is how the Sony radio is wired to existing system?


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## ANDRESVELASCO (Dec 7, 2015)

thundeer said:


> One final comment on how the tablet outputs audio: I specifically wanted the tablet output from a USB audio DAC for a cleaner signal. We chose a DAC that does not require a separate power switch or a power supply, so that it turns on automatically when the car is turned on. This also allows us to not require a separate cable connected to the 3.5mm audio output on the tablet, again, a cleaner install.


Wich device is this?


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## naiku (May 28, 2008)

ANDRESVELASCO said:


> Wich device is this?


Sabre USB DAC is a good one to use that works nicely with the Nexus 7. It's what I use and comes right on as soon as the tablet powers up.


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