Car Audio and Tablet Install in a 2008 IS250
07-08-14, 12:04 PM
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Car Audio and Tablet Install in a 2008 IS250
Hello all, I had a Nexus 7 tablet professionally installed into my 08 Lexus IS250 by Bing and Joey over at Simplicity in Sound, here is their build log:
http://www.diymobileaudio.com/forum/...xus-is250.html
and also the build log for the actual car audio installation and setup from 2 years ago:
http://www.diymobileaudio.com/forum/...oni-morel.html
I just wanted to share some details for other people who are attempting a build/setup like this themselves, I have gotten plenty of useful information from this forum and would like to contribute by posting up my findings and research to make it easier for the next person. Thanks!
______________________
List of Tablet Features:
- Tablet turns on when car is turned on (IGN/ACC), turns off when car is turned off. Minimal battery drain when car is off (<1% per day)
- CyanogenMod 11 and custom kernel installed: full customization of tablet settings (CPU/GPU tweaks, battery life optimization, screen auto brightness curve, etc.)
- Tablet physical buttons not needed: tablet can be rebooted or put to sleep (screen off) using on-screen software buttons; tablet can be turned back on (double tap on screen to wake) without pressing the physical power button
- Steering wheel controls (volume down, volume up, previous track, next track, mode) are mapped to android volume up/down, previous/next track, and back/home buttons, no need for physical tablet volume buttons
- Incoming calls and text messages are shown on tablet screen. Can reply to texts, answer calls from tablet screen directly, still requires bluetooth headset or car kit/headunit
- Rearview camera feed available on tablet screen (RCA or USB webcam) through Dashcam app (has to be started manually)
- USB audio output to a DAC (digital-analog converter) of your choice for high quality sound output (note: not all DACs compatible)
- Voice commands through Google for navigation, etc. https://support.google.com/websearch.../2940021?hl=en
*Wifi connection to phone tethering required for maps/navigation and other apps
______________________
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/1...it?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 in his log, the original idea was similar to previous tablet installs (see their previous work here: http://www.diymobileaudio.com/forum/...a-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/...ouble-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 ****). 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, 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 (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.
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.
http://www.diymobileaudio.com/forum/...xus-is250.html
and also the build log for the actual car audio installation and setup from 2 years ago:
http://www.diymobileaudio.com/forum/...oni-morel.html
I just wanted to share some details for other people who are attempting a build/setup like this themselves, I have gotten plenty of useful information from this forum and would like to contribute by posting up my findings and research to make it easier for the next person. Thanks!
______________________
List of Tablet Features:
- Tablet turns on when car is turned on (IGN/ACC), turns off when car is turned off. Minimal battery drain when car is off (<1% per day)
- CyanogenMod 11 and custom kernel installed: full customization of tablet settings (CPU/GPU tweaks, battery life optimization, screen auto brightness curve, etc.)
- Tablet physical buttons not needed: tablet can be rebooted or put to sleep (screen off) using on-screen software buttons; tablet can be turned back on (double tap on screen to wake) without pressing the physical power button
- Steering wheel controls (volume down, volume up, previous track, next track, mode) are mapped to android volume up/down, previous/next track, and back/home buttons, no need for physical tablet volume buttons
- Incoming calls and text messages are shown on tablet screen. Can reply to texts, answer calls from tablet screen directly, still requires bluetooth headset or car kit/headunit
- Rearview camera feed available on tablet screen (RCA or USB webcam) through Dashcam app (has to be started manually)
- USB audio output to a DAC (digital-analog converter) of your choice for high quality sound output (note: not all DACs compatible)
- Voice commands through Google for navigation, etc. https://support.google.com/websearch.../2940021?hl=en
*Wifi connection to phone tethering required for maps/navigation and other apps
______________________
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/1...it?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 in his log, the original idea was similar to previous tablet installs (see their previous work here: http://www.diymobileaudio.com/forum/...a-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/...ouble-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 ****). 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, 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 (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.
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.
Last edited by thundeer; 07-28-14 at 01:04 PM.
07-08-14, 01:43 PM
#2
Beautiful work and great effort. I know Bing does great work and have seen some of the cars he's done along with his wagon. I met him at one of the SQ competitions he holds in San Jose. Nice work on the complete project and hope to see it in person someday.
07-09-14, 04:10 PM
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Thanks all for the kind words! I've let Bing know to keep an eye on this thread as well if you guys have questions about the build, I can answer other questions as well regarding the setup and what it takes to get it working for a custom install in our cars.
I also know that another member recently posted a build with a full size iPad that is similar, but with the stock amp I think?
I also know that another member recently posted a build with a full size iPad that is similar, but with the stock amp I think?
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01-09-15, 12:28 PM
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Question
My name is Frank, I have mounted my Monster M7 tablet with a single din tucked in the dash, radio has aux and usb so thats how the tablet is hooked up. Now the problem im having is its losing about 10 to 15 percent battery per day, I have tasker app set up the best I can but I know it could be better. Now my question is what what software do i need to install fpr it to function like yours or do i need a nexus 7, thanks.
01-12-15, 10:30 AM
#10
Wow, that looks amazing! Would love to see Lexus offer an option to replace the proprietary NAV screen with an Android tablet like this, but of course the tethering requirement would ruin Google Maps functionality for the typical non-tech-savvy customer.
01-30-15, 04:24 PM
#14
My name is Frank, I have mounted my Monster M7 tablet with a single din tucked in the dash, radio has aux and usb so thats how the tablet is hooked up. Now the problem im having is its losing about 10 to 15 percent battery per day, I have tasker app set up the best I can but I know it could be better. Now my question is what what software do i need to install fpr it to function like yours or do i need a nexus 7, thanks.
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