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Professional Development Board LED Display — Parallax Forums

Professional Development Board LED Display

hitechartisthitechartist Posts: 5
edited 2012-12-04 14:35 in Propeller 1
My disclaimer.... I'm a really new beginner.
I bought the Professional Development Board quite a while back and I'm just now getting the opportunity to try it.
Its the Rev A Part Number 321111 and has the white test board on it.

I would like to see if I can light up the multi segment led display that's on the board.
Can anyone tell me how to accomplish this?

Thanks!

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2012-12-04 09:41
    There's an object in the Propeller Object Exchange that does this (here). Have a look at the comments in the source code.
  • hitechartisthitechartist Posts: 5
    edited 2012-12-04 09:45
    Great! I am downloading and printing it! Does it require hooking up anything or is it possible to use the display without wires?
  • Mike GreenMike Green Posts: 23,101
    edited 2012-12-04 10:03
    As with all the Professional Development Board components (pushbuttons, ICs, LEDs, geegaws), you have to connect the parts you want to the Propeller or to each other as needed.
  • hitechartisthitechartist Posts: 5
    edited 2012-12-04 10:05
    I wonder if there is a schematic to hook up this project?
  • Mike GreenMike Green Posts: 23,101
    edited 2012-12-04 10:11
    No, but here are the comments from the object: 
    lowChar  = 0                  'Rightmost character cathode pin
  numChars = 6                  'Number of characters in display
  Segment0 = 6                  'Segment start pin

    PUB Start(charRt, chars, s0, enabled)
''Start the display
''Parameters:
''   charRt - the cathode pin number of the rightmost character
''   chars - the number of characters to display  (up to 14)
''   s0 - the pin number of segment 0 (segment a1)
''   enabled - the initial enabled state
    The constant definitions in the demo program assume that the display digit cathodes (the bar on the schematic) are wired to Propeller pins 0-5 with the rightmost digit connected to I/O pin 0. The anodes (the triangle) are wired starting at Propeller I/O pin 6 with the anode segment a1 connected to pin 6 and the other anode segments connected in order. Look at the schematic for the Propeller Professional Development Board for the pin connections to the socket on the Board (on page 3). It should be fairly obvious.

    The above comments about "bar" and "triangle" refer to how LEDs are shown on schematics. On page 3, the schematic uses a picture of the display digits without the schematic symbol for an LED. You'll see if you look on other pages with LEDs shown.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-12-04 11:14
    Someone on the forum (IIRC his first name is Tony) made a PCB with some '595 shift registers that lets you control the LEDs with only a few Propeller pins.
    If you're interested and can't find the thread, let us know. One of us might remember enough key words to help you find it.

    I think those 16-segment displays look really cool but I rarely use them. It's so much easier to output to a terminal window, TV or serial LCD.
  • hitechartisthitechartist Posts: 5
    edited 2012-12-04 11:21
    I tried to search and find it but couldn't.
    So any help with that PCB would help.
    Thanks!
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2012-12-04 11:28
    This is the thread:

    http://forums.parallax.com/showthread.php?129182-New-LED-driver-for-PPDB-Now-Available&highlight=development+board

    I have one of the boards and am happy with it. Simplifies the wiring and you only need a few Propeller pins to drive all the displays.

    Robert
  • tonyp12tonyp12 Posts: 1,951
    edited 2012-12-04 11:35
    yes i still have them for sale, only uses 1 prop pin.
    mqdefault.jpg?v=50be537a
    http://youtu.be/LriHbhNR0TI

    To order one:
    https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=NVXC2URAZ8CS4
  • hitechartisthitechartist Posts: 5
    edited 2012-12-04 12:18
    Great! I just ordered one via paypal!
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2012-12-04 12:30
    There are two different versions of these boards. I must have the earlier version which uses three pins.

    Do you have the latest drivers for both versions?
  • tonyp12tonyp12 Posts: 1,951
    edited 2012-12-04 12:46
    Until Dec24, I will ship one FREE 1-wire version to anyone that ordered the 3 wire version a year ago.
    Just PM (with any new address etc) and will check my order records for a match.

    here is the old thread for it.
    http://forums.parallax.com/showthread.php?134106-Updated-17seg-LED-driver-for-PPDB-now-available.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-12-04 13:43
    tonyp12 wrote: »
    Until Dec24, I will ship one FREE 1-wire version to anyone that ordered the 3 wire version a year ago.
    Just PM (with any new address etc) and will check my order records for a match.

    here is the old thread for it.
    http://forums.parallax.com/showthread.php?134106-Updated-17seg-LED-driver-for-PPDB-now-available.

    Why? I have two of the three wire boards and they work just fine. I feel like I got what I paid for.

    It would be fun to try a one wire board (an interesting idea) so I'll probably send you a PM but I sure don't feel like you owe me anything.
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-12-04 13:49
    Duane Degn wrote: »
    Why? I have two of the three wire boards and they work just fine. I feel like I got what I paid for.

    It would be fun to try a one wire board (an interesting idea) so I'll probably send you a PM but I sure don't feel like you owe me anything.

    Very generous offer, Tony. I fell pretty much the same as Duane. I have one 3 wire and would only be getting the one wire to play with. It's people like you on the forums that make this a special place!
  • tonyp12tonyp12 Posts: 1,951
    edited 2012-12-04 13:53
    Parallax have been good to me, I'm just passing it on.
    The 3wire 17Seg was the first product that got me started in pcb design and this is my holiday gift.
    As as Prop pins are valuable, saving 2 pins is pretty important.

    I will release the schematic soon, as you may want to use these type of 17seg LEDs in your own design one day.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-12-04 14:35
    tonyp12 wrote: »
    this is my holiday gift.

    Thank you for the gift. It makes me feel better to think of it that way. I didn't want you to feel like you owed us(me) anything.

    I use shift registers in a lot of my projects, it will be interesting to see if I can use your method to save a couple of pins. I assume the one pin trick is only an option when refresh rate isn't critical (you don't need to explain this to me, I'll go read the other thread).

    Does anyone have a good source for 16-segment displays? IIRC, I think Parallax had to test each module and grouped them by brightness so each PPDB had modules with matching brightness levels.

    I purchased some surplus modules when I was new to microcontrollers (a few years ago) but they were 14-segment instead of 16-segment displays. The extra two segments are important in getting good looking characters. As I mentioned earlier in this thread, other display types are generally easier to use than these displays but I think these look really cool and I'd like to find a source of display modules so I can start including them in my projects.

    Thank again Tony.
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