No announcement yet.

ALCAS (A Linux Car Audio System)

  • Filter
  • Time
  • Show
Clear All
new posts

  • ALCAS (A Linux Car Audio System)

    Update below!

    Car: 1991 Peugeot 205 XE
    Engine: 3 cylinder 1.0L

    Processor: Intel Pentium 133
    Case: A wooden box (not built yet)
    Power: Homebrew powersupply from (not built yet, ordered the parts....)
    Memory: now 64MB instead of 16 MB, to speed up compiling.
    Storage: 20GB Seagate 5400rpm (for mp3s), 8MB CF-card (for OS)
    Sound: Soundblaster AWE 32
    Network: 10Mbit NE2000 clone
    Motherboard: some sort of pentium 1 board
    Videocard: VGA with 512KB (the computer doesn't boot without one )
    Display: Character LCD 20x4
    Radio: FM tuner (Aimslab)
    Control: Infrared remote control (lirc)

    alcas linux (Based on slackware 8.2 and only 6 MB big, uncompressed that is)
    mpg123 0.59r (mp3player)
    alcas (a program that: reads joystick input, handles playlist, controls the lcd, controls the FM tuner, controls mpg123 and controls the volume)

    Extra info:
    As you can see I have a minimal system (the car included......) I put a lot of effort in making the OS and alcas. Minimizing the OS and putting it on a CF-card make the computer boot in less than 25 secs.
    Making alcas myself gave me the total freedom on how it should work and how it can be operated.

    Project site: For more info on how I'm building my system.


    Ofcourse remarks and suggestions are welcome.
    Free circuit designs at!

  • #2
    put a / after the url's to get them to work.


    • #3

      - Updated the website: .
      - completed CF-card section
      - made a download section
      - added the disclaimer
      - etc. etc.

      - Finally the parts for my power supply came in and I'm planning to build it this weekend.

      - Replaced the motherboard, now I can disable the RAM check at boot.

      What's to come:

      - Schematic of my startup/shutdown-controller. It will work with a delay for switching a relais on and off. interfacing with the computer will be done using the parallelport.

      - Pictures of my powersupply building process.

      - Design of the case.

      Suggestions, idea's and comment are welcome
      Free circuit designs at!


      • #4


        There has been an update on my site:

        - made a logo:
        - made a picture galery.

        Currently I'm building the powersupply.

        Possibly I will not use a gamepad for input but an infrared remote control in conjuction with lirc and a homebrew receiver.

        That was it for now, more to come...

        Free circuit designs at!


        • #5
          that's lookin like a good setup man. i like how ur makin that **** power supply and stuff.

          good job! keep it up
          MP3 GT


          • #6
            No luck yet

            So far no luck with the powersupply yet.... I completed it today, but i doesn't work yet

            12V is nice and steady until you connect something to it.....

            Let's hope this works out ok......
            Free circuit designs at!


            • #7
              hey man, good luck with it. im sure everything will turn out o.k.

              MP3 GT


              • #8


                Again an update on my progress

                While still busy with the powersupply, I made some pics of the different menus and screen shown on my character lcd. Below an example is found, it's the main menu. Yes I know the photo's are a bit crappy, but the lcd looks better in real life.

                Look at for more pictures and information on the project in total.

                Furthermore I made my homebrew receiver (see for more info) work with my soft-ware. This is the receiver:

                So from now on, no more gamepad but a remote control.

                News on the powersupply will come as soon as it works....

                Free circuit designs at!


                • #9
                  Thanks for posting your updates. I'm still using a basic system (p166) only for mp3 playback, no dvd's or anything. I still haven't installed an lcd display yet. So I truly appreciate your updates on your progress.

                  Thanks again.


                  • #10
                    powersupply work!


                    The powersupply works!

                    The hardware power consumption is 18W. The PSU's efficiency is 69%. So the carputer consumes 26W (less than a headlight ).
                    I might use a piezo-electric-element for cooling afterall, since cooling only 26W is not that much. Then I can completely close the case for protection against moisture.
                    Free circuit designs at!


                    • #11
                      What did you do to make it work? What were the problems?

                      I am concidering making that power supply as well....



                      • #12
                        First of all, the reason the PSU did not work at first is probably my very own fault.... the design is OK.

                        The 12V section should give +12V and -12V (using the teroid). The +12V was ok but somehow I did not get -12V, -6 at max when nothing was connected to it. Connecting something resulted in a drop to -0,11V or even worse.
                        Now if you want a teroid to work, you need an altering current, not a direct current. So my guess is that, somehow the switching regulator does not work correctly on my circuit.
                        Since I do not need the -5V, I adapted the windings on the teroid so that in stead of -5V I get -12V out of the 5V section.
                        Please not that this is not a good thing to do i you want a high efficiency. I my case the computer uses 18W in total. So even with a efficiency of 50%, 36W power consumption, can be lived with. The efficiency of my PSU is 69%.
                        To test if your computer can do without -5V remove the -5V pin with the white wire form connector P8. Make sure the lose pin does not touch anything while testing!!

                        Free circuit designs at!


                        • #13
                          Yesterday I updated my website again.

                          I have made some progression.
                          I'm not using a gamepad but a infrared remote control for input. To make it work I made some changes is the joystick_interface. Not a nice solution, but it works for now.
                          The LCD screen will not be visible when the carputer is off. A small piece of the dash will be hinged covering the display when closed and visible when open. To open and close it a servo, like the ones used in model cars and planes, is connected to the second parallel port. The 2nd parallel port will also be used to turn on the amp after the carputer has booted, because this horrible noise comes out of the soundcard when initialised. Posibble other things can always be added, there are 11 bits free for output.
                          Software to control the servo is written already. A little crappy, but it works. There's a timing problem which I could solve by using either a real-time kernel or some dedicated hardware. But like I said, it works, for now at least.....
                          I have to make pictures of the servo and the the place in the dash where the display is to be mounted.

                          The priority for now is getting the computer in the car. This means that I have to buy wires and install the wires in the car. The hardware section of my website shows my wiring diagram. And offcourse the above metioned construction has to be made.... In general my software is ready. I want to postpone the software development to spend my time getting the stuff in the car.

                          That's for now, I hope to show pictures of the computer (being) built in soon.

                          Visit my website for detailed information.

                          Free circuit designs at!


                          • #14
                            Ok my project is finally finished. I put the pic on my website. There's just some bugfixing to do.
                            Free circuit designs at!