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Does anyone know how I may be able to drive this display with a propeller? — Parallax Forums

Does anyone know how I may be able to drive this display with a propeller?

rwgast_logicdesignrwgast_logicdesign Posts: 1,464
edited 2013-04-10 22:32 in Propeller 1
IMG_20130409_144024.jpg
IMG_20130409_144009.jpg


I pulled this thing out of an radar detector a while back, and am interested in getting it running. The problem is I do not know if displays like this need an interface chip like a parallel LCD, or if you just drive the LEDs like you would a seven segment, i don't even know what these displays are called. The display is 8 digits and has a grid of leds in each digit display.
IMG_20130409_144024.jpg
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IMG_20130409_144009.jpg
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Comments

  • kwinnkwinn Posts: 8,697
    edited 2013-04-09 16:23
    Are you sure those are leds in the display? That looks more like a vacuum fluorescent (gas discharge) display to me. If the face is glass that is almost certainly what it is.

    Whether led or VF it is a 6 character display using a 5 x 7 matrix for each character.
  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-04-09 16:31
    Im not sure if it is LEDs or not,it just looks like a bunch of copper traces with a tiny spec where each light is, the specs shine a bit when they catch the sun. The casing is most definately plastic. Do these displays use common hook ups like a 7 segment, one could figure out by looking at others? I have never seen anything about using a display like this online, but they look really nice I think. I would think the bottom 7 solder pads flip each digit on and off by beyond that i am clueless, there's not 35 pins for each dot in the matrix.
  • BigFootBigFoot Posts: 259
    edited 2013-04-09 17:05
    It looks like a gas discharge (orange) or vacuum fluorescent (blue) display to me. As I remember the gas discharge displays need around
    100-200 volts and the VF displays run off around 50V. If you check out the power supply that powered it you could probably figure out which.
  • fengfeng Posts: 39
    edited 2013-04-09 17:08
    Maybe?

    https://www1.elfa.se/data1/wwwroot/assets/datasheets/hdsp-253x_eng_tds.pdf
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2013-04-09 18:12
    Agreed, feng. They're LEDs.
    They have the look of "smart-displays".
    Serial, SPI most likely.

    https://cobra.com/downloads/manuals/XRS9630_MANL.pdf
  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-04-09 18:14
    Yes this was out of a 12v cobra unit, which used an atmega32 micro. So am I basically never going to get this to work with out a data sheet?
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2013-04-09 18:16
    You should leave this sort of thing inside of whatever it's in, you stand a better chance of finding out how it works that way. It's basically a custom build for Cobra.

    Keep on "googling"!
  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-04-09 18:54
    That was the plan originally, I wanted to try to extract the eeprom and use the hole thing as a dev board, but I pluged one of those universal wal warts in to it backwards :/ fried a bunch of stuff!! Anyways thanks for the information ill see what I can figure out from here
  • kwinnkwinn Posts: 8,697
    edited 2013-04-09 21:35
    feng wrote: »
    Maybe?

    https://www1.elfa.se/data1/wwwroot/assets/datasheets/hdsp-253x_eng_tds.pdf

    I think feng may be right. Wouldn't hurt to try hooking it up using that data sheet, although if power was applied in reverse it may be fried.
  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-04-10 21:28
    Feng, THANK YOU! While the data sheet you provided was not correct it helped me identify my part! The Avago HCMS-2973

    http://www.digikey.com/scripts/DkSearch/dksus.dll?lang=en&keywords=hcms-2973&WT.srch=1&cur=USD

     I was super excited I could buy more of these, till I saw they were $35 bucks in singles! :/ Even in bulk this must be the main cost of the radar detector, I like these type of screens a lot, but at $35 bucks I would expect it to at least be a bit bigger
  • NWCCTVNWCCTV Posts: 3,629
    edited 2013-04-10 22:32
    at $35 bucks I would expect it to at least be a bit bigger
    HMMMM, Where have I heard that before?????
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