hacker

thauta

A simple car media project

The goal

• Get rid of the ancient, original CD player which doesnt even know how to play MP3s
• Have a large MP3 collection available
  • Should be easily browsed based on different keywords (artist, song name, albums, playlists etc)
• Boot up quickly, in less than 10 secs
• Good audio quality

Components

• The first version had a simple embedded device which emulated a CD changer while playing songs from an iPod
  • The quality of audio was terrible and the device was prone to lock-up
• For the second version, a quickly booting carpc with a 7" touch screen was built
  • It turned out that the screen didn't have proper EDID information and the touch part was partly faulty
• The current, third version has a Samsung Galaxy Tab 2 7" Wifi tablet with a bezel embedded into the dashboard
  • The audio goes through the standard 3.5mm connection
  • For charging, a 2A USB car charger is required
  • A 32Gb microSD card provides space for music and video
  • A protective, reflection redusing film applied on top of the touch screen
  • Poweramp as the music player

    • https://play.google.com/store/apps/details?id=com.maxmpz.audioplayer&feature=search_result

  • For handling automated start-up, 3G connection establishment, media play, sleep etc functions, an app called Tasker can be bought from the Google Play store

    • https://play.google.com/store/apps/details?id=net.dinglisch.android.taskerm&feature=search_result#?t=W251bGwsMSwxLDEsIm5ldC5kaW5nbGlzY2guYW5kcm9pZC50YXNrZXJtIl0.

  • The stock Samsung 4.0.4 Android was replaced by Cyanomodgen 10.1 (Android 4.2.2) but this is not necessary

  • Its now possible to sing karaoke!

    • This small microphone mixer was added to the system between the tablet and an amplifier: http://www.ebay.ie/itm/karaoke-mixer-dual-microphone-stereo-music-stereo-output-/181093548605?pt=AU_Karaoke&hash=item2a2a04423d

    • Note: the mixer was previously sold from a US location with lower postage

Installation

The following pictures show how a tablet can be installed in case someone else would like to have a similar setup:

First, install 2 strips of velcro for securing the tablet to the right place. Also, 2 strips of metal are used together with the velcro to attach the tablet to a 7" screen bezel.

Make sure that the tablet's screen doesnt have any offset.

Try to find small screws for making this connection as they can create a problem later on when installing the bezel to the dashboard. Also, unlike in the picture, a second strip of metal is needed to secure the tablet firmly to the bezel.

Also test that the charging/sync cable and the audio cable can fit to the dashboard. In this case, small modifications were needed (cut pieces out of the way) but they are invisible once the bezel is in place. Also, the original CD player look can still be restored in wanted. The other end of the USB cable was run to the glovebox inside the dashboard so that its easy to sync new music or video to the device from a laptop. For that, the AC controls together with the whole lower dashboard had to come off but its really a simple job and doesnt take more than 1h.

First tests with the screen turned on.

It works!

Whee, it works!

Experiences

• Generally, its so much nicer to drive around now having lots of music (and some video) onboard. The tablet also works as a navigator and warns about upcoming speed cams.
• The tablet resumes from sleep quickly (in ~1 sec or so)
  • Power-on and power-off events are now handled by Tasker
• The screen is slightly larger than the bezel's inner diameter. A small piece should be trimmed away to make the tablet more usable when buttons on the far corners of the screen are to be pressed
• A tablet with built-in 3G connection would be much better if your usage needs more data
  • For example, getting a fast GPS fix requires AGPS and for that an Internet connection can be shared from a mobile phone if needed (via Wifi or Bluetooth)
    • The sharing can also be automated with Tasker but having Wifi tethering on all the time will quickly drain your phone battery
• The built-in music player of Galaxy Tab 2 is rubbish (like most of Android's music players for car use) so having a good player with EQ is really a key part of the system
• Multi-touch gestures didn't work for some reason but on-screen menu buttons work good enough ('Home', 'Back' etc)

TODO

• Find a smaller 3.5mm angled connector to shift the tablet 2-3mm to the left
• A bluetooth device that can read pressed volume buttons, ambient light level in the cabin and speed information from the car's bus and feed them to the tablet via a custom app
  • This could be implemented using Arduino + cheap chinese BT add-on board

  • More of this project here: https://www.jkry.org/ouluhack/thauta/vehicleToAndroid

• Add a USB drive for more music and video
  • For some reason, the tablet doesnt work with a USB-on-the-go cable
  • A Raspberry Pi sharing videos from an USB drive through WLAN might be nice for this purpose
• Figure out how an analog reverse camera could be used with the tablet
started
2013-03-07

CategoryProjekti