Dreamcast Maple + BASIC Stamp

Discussion in 'Modding and Hacking - Consoles and Electronics' started by Dreamcast, Jul 27, 2009.

  1. Dreamcast

    Dreamcast Intrepid Member

    Joined:
    Jul 17, 2007
    Messages:
    651
    Likes Received:
    114
    After watching Midway's demonstration of the prototype Ready 2 Rumble controller, I was interested in trying to interface the Dreamcast to a BASIC stamp. Hopefully I can use it to figure out what the Dreamcast is sending the Dreameye to get it into streaming mode (would be nice for KOS). So far I have a basic circuit of two L.E.D.s for determining logic. All of my information about the hardware protocol comes from Marcus Comstedt's research: (link). The pinout for the controller port can be found here: (here).

    To interface the Dreamcast to the board, I'm using the cable from the Dreameye since it has a connector on the end that I can plug wires into. If you open up your Dreamcast controller, you can disconnect the cable and use that too.

    Pinout of the Dreameye cable:

    Hold it so the arrow on the connector that goes to the camera is facing down and the connector holes are facing you. Pins 1 through 5 are in that order (1 - 5, left to right).

    PBASIC sync code:

    So far, the only code I have working is the sync code. If there's a better way to do this, please let me know. I know I do need to change it so it starts back at the starting over position if the levels are different.

    Is there a better way to handle the polling? I wrote a second program that groups the bits into bytes, but it's telling me both pins are always high even though the above code works meaning that they aren't. Here is the code for that:

    What I want to do with the code above is to group the bits, then send them to the PC. Afterwards, I can go through and create a graphical representation of the signal using hypens and underscores. So, the sync would look like this:

    I appreciate any help anyone with BASIC stamp or Dreamcast hardware experience can offer.
     
    Last edited: Jul 27, 2009
  2. BlueCrab

    BlueCrab Member

    Joined:
    Feb 6, 2007
    Messages:
    16
    Likes Received:
    11
    While you might discover something interesting with a BASIC stamp (like registers that might have to be fiddled with on the Dreameye), I'm pretty sure that "streaming" mode isn't any different from reading normal pictures off of the camera, its just a case of which pictures you read.

    The live image should be sitting in pictures 0 and 1 of the camera (I believe that it stores the frame for an extra frame, so it'll be in 0 the first time, and 1 the second time, but I'm not entirely sure). It should just be a matter of reading those two images, instead of the rest of the ones on the device (that's why the Dream Photo Manager always starts with image 2, that's where still images are stored starting).

    The only reason that this approach isn't implemented in KOS is because I don't know how to decode the images once I get them. They're supposably in a format called JangGu, which I couldn't find much information online about. Other than this, there may be some registers that need to be fiddled with, but I'm not entirely sure (this is where some hardware hacking would come in handy). I have no idea about basic stamps and the like, so I really can't help you there.
     
  3. T_chan

    T_chan Gutsy Member

    Joined:
    Apr 13, 2008
    Messages:
    470
    Likes Received:
    65
    The extension cables for the Dreamcast are also an option for that:
    http://www.play-asia.com/paOS-13-71-t-49-jp-70-1p.html
    They can be found for a few dollars on ebay.

    Do you have some sample files online, so that people could have a look at them ?
     
  4. Dreamcast

    Dreamcast Intrepid Member

    Joined:
    Jul 17, 2007
    Messages:
    651
    Likes Received:
    114
    Hey BlueCrab, good to see you over here. :) If I get any further on the Dreameye stuff, I'll probably move that part of the project back to dcemulation since there's more work with KOS done there.

    The idea that the frames are buffered in the first two banks is a good idea (or has it been confirmed that it is stored there?). If the buffer changes as you move the camera, that's the easiest way to tell, even if you can't decode the data. The camera has a decent speed live and, so if it's encoded, would be compressing on the fly. I'm not familiar with the hardware in the camera, but does that sound plausible? I always imagined it was sending at least a semi-uncompressed 555 / 565 frame.

    T_chan: The extension cables are a good idea, too. I was looking into ways to wrap wire around cardboard to make a piece to plug in so you wouldn't have to destroy the cable (though I never use them anyway :D).
     
  5. smf

    smf mamedev

    Joined:
    Apr 14, 2005
    Messages:
    1,259
    Likes Received:
    92
    I would usually recommend using an emulator for figuring this stuff out.
    You'd need an open source one or talk to one of the developers. I'm sure they'd be interested in adding support anyway.
     

Share This Page