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Microcontroller help. In over my head. — Parallax Forums

Microcontroller help. In over my head.

Sleeper_6Sleeper_6 Posts: 4
edited 2011-07-08 13:09 in General Discussion
Hi everyone. I'm glad to have found this forum. I saw the website on a microcontroller starter kit at Radio Shack. I'm hoping I can find some insight here, and I am willing to learn whatever I need to learn about electronics to make my project happen.

I need to build a microcontroller, whose only job is to take a short video clip, output it to an LCD screen, and loop it. I'm hoping to make it battery run. I have the soldering iron, I have the will to do it, I am just lost as to how I can go about making this.

Can anybody help?

Comments

  • kwinnkwinn Posts: 8,697
    edited 2011-07-07 16:40
    How long is "a short video clip" in minutes and seconds, and what resolution do you need?
  • Sleeper_6Sleeper_6 Posts: 4
    edited 2011-07-07 17:19
    Thanks for replying. I was hoping to get a 1280 x 720 clip that would play for no longer than 25 or 30 seconds. It could go less on the resolution.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-07 18:21
    If you are using standard video clips the micro would have to decompress the data and convert it to a video signal for display. That would be beyond the capability of most microcontrollers. I would suggest one of the small SBC's that has the hardware do that on board.
  • Sleeper_6Sleeper_6 Posts: 4
    edited 2011-07-07 21:13
    That would actually simplify things. Instead of making my own board, buy a premade single board computer. Could you help me find out what a really cost effective SBC would be?(manufacturer, distributor, etc...)

    I am assuming I would need to load some simple distro of linux with an application that would automatically cue up the video, and play it over and over again. Or is there a simpler way to program an SBC that wouldn't require an OS?

    I apologize if my questions seem simple, but I am starting out from almost no basic knowledge here.
  • Kevin WoodKevin Wood Posts: 1,266
    edited 2011-07-07 21:38
    Buy a tablet pc/netbook/iPod Touch/etc. You're very much underestimating what's required to do what you want.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-07 21:47
    No apologies required for questions.

    It sounds like you are trying to find the simplest and least expensive way to accomplish a specific task rather than taking on a project for your own enjoyment. If that is the case my approach would be to buy a complete computer (new or used) and load it with the operating system and software required (Linux or Windows). I wouldn't even consider an SBC without an operating system. By the time you add up everything needed the SBC approach is considerably more expensive unless you are planning on volume production.

    Are you under any other constraints such as physical size, power availability, or harsh environment?
  • Mike GreenMike Green Posts: 23,101
    edited 2011-07-07 21:49
    Do a web search for "BeagleBoard" and for "Gumstix". Both can run Linux and output video. I'm sure there are many others.

    You could also buy an iPad Touch to handle the video using its composite video output cable. The resolution will be lower than 1280 x 720. You can write a program using NSBasic/App Studio that can play video looping it. Since this compiles into JavaScript, you could also do the same thing with an Android device.
  • zoopydogsitzoopydogsit Posts: 174
    edited 2011-07-07 22:06
    Depending whether you need to connect to the real world you may want to follow Kevin's suggestion and aim more for the platform to meet your environment & needs. In home control groups they now use IPOD touches/IPADs/Android pads/etc as a control interface providing a web browser via a WIFI connection anywhere in their house rather than hand building a custom interface. As an example, if you want small form factor then you can pick up new/used IPOD Touch relatively cheaply, or an Android touch pad clone and for the same amount as a SBC which would still need a case/powersupply/screen, then you still need to do the coding etc. Mike made some great suggestions for potential product solutions.

    As Kwinn said, it depends on whether your doing this for the journey or the outcome.

    It would depend on whether you want to have the fun building/integrating/writing SW/ building a case/troubleshooting/etc. or whether you want to configure something pre-built.
  • wasswass Posts: 151
    edited 2011-07-07 22:09
    I'm willing to bet that one or more of the digital picture frames can do exactly what you want at the lowest price. There are several hundred to choose from, many (most?) of which display MPEG, AVI or other video formats. Just put a single video on the memory card and let it run. if you need to be able stop/start it under computer control you can probably just control the power supply -- most of these auto start.
  • kwinnkwinn Posts: 8,697
    edited 2011-07-07 23:48
    wass wrote: »
    I'm willing to bet that one or more of the digital picture frames can do exactly what you want at the lowest price. There are several hundred to choose from, many (most?) of which display MPEG, AVI or other video formats. Just put a single video on the memory card and let it run. if you need to be able stop/start it under computer control you can probably just control the power supply -- most of these auto start.

    This seems to be the best idea so far, with Kevin Woods suggestion of using a tablet/netbook/etc. a close second. Assuming that all you want to do is play a video in a continuous loop.
  • LeonLeon Posts: 7,620
    edited 2011-07-08 07:34
    This new NXP ARM Cortex-M3 chip looks as if it could be useful for that sort of thing if the OP wants to build it from scratch:

    http://ics.nxp.com/support/microcontrollers/lcd/
  • Sleeper_6Sleeper_6 Posts: 4
    edited 2011-07-08 12:43
    You've kind of hit the nail on the head. I'm trying to make my own digital frame that will display one looped image, and keep the cost down as possible. I'd like to keep my parts cost to under 50 bucks if possible.
  • LeonLeon Posts: 7,620
    edited 2011-07-08 13:09
    That isn't possible, a prototype PCB will cost more than that. Under $50 is feasible if it went into production.
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