A question about the Prop Backpack and its code

Hello!
I have a single Prop Backpack here. I use it when video as output are required for a project instead of characters on an LCD type display, (or an LED one). Are there plans at some further point in time to restart production for this device? Or failing that one are there any problems with my reproducing its functions using any available Prop board?

I am thinking that a time will surface when a breadboard built project and its display methods becomes a permanent one, and it uses the same functions as the Prop Backpack.

About my only problems are with deploying the programming to the Prop board, and assembling the gadgetry that translates video signals from the Prop into visual ones on a composite display.
--
Mascot not accepting messages but will accept free food.

Comments

  • localrogerlocalroger Posts: 3,393
    edited 2020-05-28 - 23:38:02
    The hardware for generating composite is just an array of four resistors all feeding the composite RCA jack from four contiguous byte-aligned Prop pins; you can easily see them on the backpack schematic. A similar device that is current would be the combination of a QuickStart and the Human Interface Board, which is effectively the same as the old Demoboard with composite and VGA video out, audio in and out, PS/2 keyboard and mouse. Parallax probably won't make any new products dedicated to composite since the whole TV industry has now gone digital and new sets don't have composite inputs.

    Edit: Here is a link to the Parallax doc for the backpack: https://www.parallax.com/sites/default/files/downloads/28327-PropellerBackpack-v1.0.pdf

    I would recommend using a PropMini and a breadboard to recreate the subsystems you need for it to work with a BASIC stamp. You should also be able to download the software that came with the Backpack, but you will probably have to change the clock setting for it to work with a 5 MHz crystal.
  • Which was my thoughts exactly, @localroger but, ah, I do not have an HIB here. I just looked through my entire collection of Prop related boards. They include one Prop Project board, USB and multiple QS boards. Also a batch of boards from Gadget Gangster. There was also a prototype board that matched the QS for sizing. I also came across the networking board for the QS which I never managed to get working no matter how many examples I tried.


    ---
    Mascots asleep, no messages accepted and no food required.
  • Wuerfel_21Wuerfel_21 Posts: 718
    edited 2020-05-29 - 13:28:15
    localroger wrote: »
    new sets don't have composite inputs.
    Last I knew, most if not all TVs still have some form of composite input (often either merged with the Y input for YPbPr or as part of a SCART socket). You can obviously also get terrible HDMI converter boxes for cheap (and good converter boxes for an arm and a leg...) (I say "terrible" as if the built in composite decoder in most HDTVs is any better...)

  • Wuerfel_21 wrote: »
    localroger wrote: »
    new sets don't have composite inputs.
    Last I knew, most if not all TVs still have some form of composite input (often either merged with the Y input for YPbPr or as part of a SCART socket). You can obviously also get terrible HDMI converter boxes for cheap (and good converter boxes for an arm and a leg...) (I say "terrible" as if the built in composite decoder in most HDTVs is any better...)

    Hello!
    Well @Wuerfel_21 the HDTV set w/ DVD player, which was a present from the family for my 50th does indeed have composite video inputs, and also an audio one. It also has an S/Video one. Plus the Broadcast TV one, and the HDMI connectors. And with the Backpack I was sent a while ago I was able to accomplish the majority of the development work with it, using the set's composite video input. But normally I use a display from Adafruit, they sell three sizes, I started off with this one, NTSC/PAL (TELEVISION) TFT DISPLAY - 1.5" DIAGONAL but I bought one from Micro Center which is this NTSC/PAL (TELEVISION) TFT DISPLAY - 2.0" DIAGONAL

    And I hope to track down one of these, NTSC/PAL (TELEVISION) TFT DISPLAY - 3.5" DIAGONAL

    But that's for later this season, they've got it marked as out of stock.

    And yes, @Wuerfel_21 there are such boxes out there, that will do that. It happens there are a batch of them for sale in the same location where I got the display.

    Still working out the methods to reproduce the video out functions properly. I suspect that will be the easy part. It's the input from the Stamp that's complicated.
    --
    Mascots away, no messages and no food accepted.
  • Duane DegnDuane Degn Posts: 10,119
    edited 2020-05-29 - 18:49:14
    A video out adapter is pretty simple. It's just a few header pins, a few resistors and a RCA connector. I'll try to find one of mine and upload a photo.

    If you have trouble finding a small NTSC display, I probably have a couple I'd be willing to sell you (for the same price I purchased them (plus whatever it costs to ship)). I have several of these 2.5" displays. Here's some more info on these small displays.
    I suspect that will be the easy part. It's the input from the Stamp that's complicated.

    Did you have your Stamp working with a Propeller Backpack? If so, it shouldn't be hard connect to an alternate Propeller board. I'm sure you'll get plenty of help making any changes needed.

  • Duane Degn wrote: »
    A video out adapter is pretty simple. It's just a few header pins, a few resistors and a RCA connector. I'll try to find one of mine and upload a photo.

    If you have trouble finding a small NTSC display, I probably have a couple I'd be willing to sell you (for the same price I purchased them (plus whatever it costs to ship)). I have several of these 2.5" displays. Here's some more info on these small displays.
    I suspect that will be the easy part. It's the input from the Stamp that's complicated.

    Did you have your Stamp working with a Propeller Backpack? If so, it shouldn't be hard connect to an alternate Propeller board. I'm sure you'll get plenty of help making any changes needed.

    Hello!
    I didn't answer your question. Yes I did. But not the Stamp I have out now. I didn't label the ones I use but I think that one found itself installed as the brains behind the BOE-Bot I built earlier.

    With the one I have out now, I'll need to confirm that the program on it, is the one I had running last time, it went to one of the LCD displays that Parallax sells which is the 2x16 Serial LCD if that one does contain the program I wrote several days ago, and it works the way I thought it did, which is important because the back end, a netduinio 3 (It comments about the discontinuation of the thing and the superseding of it by a different platform. Won't effect me.) was the previous one, as was the logic behind the original ideas. That is going back to a different vendor for the same platform.

    Once I get the Stamp platform tested with the :LCD display, it then becomes possible to switch to the backpack.

    As for your offer regarding displays, thank you but I have enough here for the moment.
  • Buck RogersBuck Rogers Posts: 1,798
    edited 2020-05-31 - 16:10:38
    localroger wrote: »
    The hardware for generating composite is just an array of four resistors all feeding the composite RCA jack from four contiguous byte-aligned Prop pins; you can easily see them on the backpack schematic. A similar device that is current would be the combination of a QuickStart and the Human Interface Board, which is effectively the same as the old Demoboard with composite and VGA video out, audio in and out, PS/2 keyboard and mouse. Parallax probably won't make any new products dedicated to composite since the whole TV industry has now gone digital and new sets don't have composite inputs.

    Edit: Here is a link to the Parallax doc for the backpack: https://www.parallax.com/sites/default/files/downloads/28327-PropellerBackpack-v1.0.pdf

    I would recommend using a PropMini and a breadboard to recreate the subsystems you need for it to work with a BASIC stamp. You should also be able to download the software that came with the Backpack, but you will probably have to change the clock setting for it to work with a 5 MHz crystal.

    Hello!
    Something else, while reorganizing the folder which contains my Basic Stamp files and accessory PDF ones and subfolders on everything else, I came across a zipped one which says its the programs for the Backpack. It would seem that I did download everything for it, then afterall.

    Now the work of making this current idea to work with the Backpack can start after more tweaks to the code whilst it is using the LCD one as its display.
  • Update:
    I finished that part yesterday, around the SpaceX launch. And today I came to a conclusion, there's nothing there, there, to prove. Yes I'll see stuff ASCII stuff spooling all over a video display, but that's all.

    So thanks everyone for your great ideas, and better advice. Next? That's the big ticket, and sadly it's not being covered here.
Sign In or Register to comment.