Custom Double-Din Mount For Nexus 7 Carputer

Nexus 7 Dashboard

Many new vehicles come with computers built into the dashboard. They can be very handy with features like GPS navigation, Bluetooth connectivity, and more. Installing a computer into an older car can sometimes be an expensive process, but [Florian] found a way to do it somewhat inexpensively using a Nexus 7 tablet.

The size of the Nexus 7 is roughly the same as a standard vehicle double-din stereo slot. It’s not perfect, but pretty close. [Florian] began by building a proof of concept mounting bracket. This model was built from sections of MDF hot glued and taped together. Plastic double-din mounting brackets were attached the sides of this new rig, allowing it to be installed into the dashboard.

Once [Florian] knew that the mounting bracket was feasible, it was time to think about power. Most in-vehicle devices are powered from the cigarette lighter adapter. [Florian] went a different direction with this build. He started with a cigarette lighter to USB power adapter, but he cut off the actual cigarette lighter plug. He ended up wiring this directly into the 12V line from the stereo’s wiring harness. This meant that the power cord could stay neatly tucked away inside of the dashboard and also leave the cigarette lighter unused.

[Florian] then wanted to replace the MDF frame with something stronger and nicer. He modeled up his idea in Solidworks to make sure the measurements would be perfect. Then the pieces were all laser cut at his local Techshop. Once assembled, the plastic mounting brackets were placed on the sides and the whole unit fit perfectly inside of the double-din slot.

When it comes to features, this van now has it all. The USB hub allows for multiple USB devices to be plugged in, meaning that Nexus only has a single wire for both power and all of the peripherals. Among these peripherals are a USB audio interface, an SD card reader, and a backup camera. There is also a Bluetooth enabled OBD2 reader that can monitor and track the car’s vitals. If this project seems familiar to you, it’s probably because we’ve seen a remarkably similar project in the past.

23 thoughts on “Custom Double-Din Mount For Nexus 7 Carputer

  1. I really need to finish mine. I did something very similar but instead I designed 3D printed brackets that I just slide the tablet into. Those work very well for my car. Instead of a cigarette lighter adapter, I found some 12 to 5V 3A automotive modules on ebay. Running this through an OTG USB hub which then connects to the tablet to both charge and provide USB connectivity.

    For the audio connection, a cheap pyle audio amp was modified with a bluetooth audio adapter.

    I wanted to also do wireless charging with a Qi charger, which supposedly will output 1A (I am doubtful). But the battery drains faster than the charger can hold it up, though the charger modification does register. Question for someone… Would it be as simple as getting a dual Qi charger and 2 receivers and wiring them in parallel to get 2A? I have no experience with this technology.

    Tablet was originally an android tablet, but I have switched over to a cheap windows tablet.

    I would love to make it completely wireless, but that’s where I have been stuck. If not wireless, I would like to design in a docking connector into the back with all the needed signals.

    1. Oh wait… I should read comments before asking obvious questions. As far as QI goes you need to make sure that 1) You have a sufficient supply of power, 2.1 or 3 amp if possible and 2) Your QI base has 3 coils, as 2 coil will not be sufficient for your power consumption. It will get pretty warm, but fortunately you have A/C vents so there’s a simple solution to that problem right there.

      1. Ahh that could be it. 3 coils in the base then and just use a bigger input supply? But I would only need one receiver on the tablet? I don’t know how thin the wires are, is that an issue (or perhaps that’s what generates the extra heat?)

        1. The induction causes loss of energy due to heat so 3 amps of power gives you less than 2 amps of inductive charging. Anyway, if I read correctly the Qi charger for the Nexus 7 uses those side contacts so I would suspect the answer to your question is Yes. Other android devices (such as Nexus 6) have the Qi charging ability built-in. I picked up a Qi-compatible charging back for my Galaxy S4 for $15 or so which works very well. I make it on a 3 hour car trip with no issues as long as I don’t leave my screen on all the time.

          1. I’ll have to experiment some more. The receiver is for a Nexus 7, but I am not using a nexus 7 tablet. I hacked it into my tablet. I was running the base off a 2.1A USB charger. The tablet seemed to register the charger was present, but the battery just kept draining as if no charger was present.

  2. As a long time AppRadio user over two iterations of that hardware; this is the way I’m going next. I’ve had it with poor app stability, brake switch interlocks that’s borderline retarded on its implementation and limits the snot out of its usefulness (although I suppose we can thank greedy litigators for that) and a massive cable required for it to operate with the phone.
    The possibilities here are as diverse as the ideas the builder can come up with. All I wish for all to consider is this: mount it properly. Support it very well and make sure it’s safe. It will save your dash (resale value, upset spouse etc) and in a nasty crash, will save your life.

    1. I think the stock launcher is fine as long as you keep your screen organized. :-) I, for one, cannot wait for voice recognition to get out of uncanny valley so I can have a device I can talk to 100% and not look at while driving.

    2. I agree that stock is fine, but if you want it to look a little more zingy and new you can try smartlauncher I have had no problem with this running on 2.3 on up :) I usually just globally turn off animations though as they eat up clock cycles and are only pretty to others. You can try spare parts app for tuning the animation level to your needs. Best of luck.

    3. Stock launcher is OK but the real issue is stock icon size. trying to tap a 1/2″ icon at arm length while driving is difficult and dangerous. You can see in my setup how I’m using Desktop Visualizer and Nova Launcher to setup giant buttons.

      I also use voice commands frequently because Android can now listen for “OK Google” commands at all times when charging. Commandr is a nice tool with extra voice commands Google should have included like “next track” and “mute”.

      GMD Gesture Control also works quite well to let you use custom gestures to launch apps or Tasker commands.

  3. this counts for ‘integration’ ? looks like its just velcro’d to the dash. what is your anti-theft story? no way to hide it? not even a motor door to hide it?

    come on, guys.

    I wish I could post a photo of my install, but that would defeat some of the anti-theft stealth features. what I can say is that I have a fake faceplate (double din style, so it has lots of room behind it) and when you park, you can’t see that its NOT a stupid oem double din radio. no one would break in to take such a thing and for 10 yrs that I’ve owned the car in the bay area, not a single break-in. I used custom molded plastic bezels (heat-formable plastic, matching the woodgrain of my car’s interior) and its all behind a ‘sawed off’ oem faceplate. the real face that came with the car and was easily disassembled to create JUST the face, as a thin layer. then, put whatever you want behind it. lcd, gps, preamp, whatever.

    this is just a velcro install. I’d expect a bit more than that for a HAD article.

    (and lets not even talk about the HORRIBLE idea of a touch interface in a car. just because you can, does not mean you should! have people learned nothing from decades of successful user-interface design on things like planes and cars where touch panels have no business at all being?)

    1. “what is your anti-theft story?”

      He just… removes the… uh… TABLET ??

      Really, you had to go there just to boast about your super-mega-awesome-system that you are (shocker) unwilling to actually show us? I mean because we might somehow seek out your exact car from a dash picture and steal your super-mega-awesome-system-that-nobody-else-here-could-possibly-just-build-themselves…


      1. yes, you DO need an anti-theft story if it mounts in a car and can be left there. and if its detachable, it leaves an indication of that, there.

        maybe you don’t live in a crime area or drive into them, but having lived in the boston area (now in the bay area) I am very aware of the realities of car audio stuff ‘being taken away’. and it hurts badly when you lose stuff that you put so much personal time in, to thieves. been there, had it done to me, don’t want to go thru that again.

        so, yes, I do criticize dumb installs like this. not having it be hidden is a bad idea, especially for the HAD crowd. we should expect a bit more from our own hacker community.

        plus, it sticks out like a sore thumb. why use a model that is too large to fit? I say again, it looks equivalent to a velcro slam-job and its not very attractive at all. if it was smaller than the din opening and was recessed (like I was suggesting with my install design) then that would have been at least a proper DESIGN. instead, this was glued to the front, just not using glue, but still has the same dorky effect.

        I listed my design because it seems that its not obvious how to secure (or at least TRY) custom car audio installs. these days, I would not do an install unless it had a good security story to it, and that usually involves hiding things so that thieves don’t even know there’s a custom install there.

        and aside from all that, having a touchscreen in your car’s dash is really dumb. yes, tesla does it and they are dumb for doing that, too. there is no good safety story for using touch interfaces in a moving car. its accident-city just waiting to happen. with real knobs, you can feel your way around and not have to take your eyes off the road. NO SUCH THING with touch interfaces.

        so, I dislike this idea for 2 key reasons: the install is ugly and has no anti-theft features (removing it leaves a telltale, so that is not very smart) and the touch screen idea is obvious, not inventive and not a good idea for the car.

        now, use the display as a read-only device, add actual physical controls in a panel below it, say, and scan the physical rotary encoders and buttons with software and action on them if pressed. THAT would be a great HAD article. but I’m sorry, this one just isn’t. its still nothing more than a glorified velcro install. custom wiring and bracket does not make a ‘hack’; its just a normal every day car audio installer job that any of them could do in a few hour’s time (I used to do car audio stuff when I was younger and I’m aware of how good some car audio install shops can be and how truly creative they can be)

  4. “usb audio interface” What is this?

    I was wondering how you managed to power the car’s speakers with just the audio output of the tablet. Do you have an amplifier running? For a write up about using a tablet as a car computers.. there’s really not a lot of information about how you actually “technically” do it.. Just how you “physically” mounted it.

    1. Most reasonably good android tablets have usb host as well. If you plug in a usb sound card….you can use it. The cable is called USB OTG (on the go) and with some tweaking allows it to charge the tablet while it is behaving as a host.
      Other things that work on android usb: mouse/keyboard, midi, usb2serial, hard drives/flash drives…

  5. If a Nexus 7 is about the same size as a double DIN car stereo, I have a suspicion about the Apple Car (or Google Car, or whatever).
    Replace the USB / lightning port with a variant of the magnetic connector on Mac laptops. Include a device in purchase of a car. Feeling fancy? Let it replace your car keys: proximity sensors are already at work.

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