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Need help Using the matrix orbital 4x20 display older model — Parallax Forums

Need help Using the matrix orbital 4x20 display older model

voodoofishvoodoofish Posts: 67
edited 2006-02-04 04:59 in BASIC Stamp
I had purchased the matrix orbital 4x20(pn 30058) blue backlit display a while back for a project. I recently tried to set it up and test it out, but have not really found too much info on doing this.

I started with reading the manual, which doesn't really give any examples of code or anything as well as going through the bs2 manual and reading up on the serout command. I also tried reviewing the code from the new 4x20 display to see if I could get something from that, but no dice. I tried changing vars around to match my setup and what I was trying to send...
When I power it up I get the display to show me the initial screen.

I've tried something along these lines just to clear the screen.

serout 1,32[noparse][[/noparse]254,88]

I also tried to use the
high 1 pause 500 from the code for the other 4x20 display just to see if that would make a difference

I made sure that I was on pin one, I made sure that I was sending to the rx connection on the display, though I did attmept this on the tx pin on the display by accident....(could I have fried something?)
I'm using a six volt battery pack connected to the 9v connector(since it's knocked down to 5 anyway)

There were some pauses to see where the program the process was as well as debugs to show me, but nothing happens...the screen stays on it's inital welcome display and thats it.

What am I doing wrong?
is there some code that I can use to test it out on my homework board and the lcd display??
Should I test the i2c bus?(I have a new bs2p thats still packaged for future stuff)
Thanks for any help.

Mark

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-02-02 00:35
    voodoofish said...
    serout 1,32[noparse][[/noparse]254,88]
    32?· Is that a valid baudmode?· I think that one ships 9600 (configured by the jumper blocks on the back.)· 8n1 TRUE would be SEROUT 1, 84 for a BS2, 2e, 2pe.

    Which STAMP are you using?
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-02 00:57
    actually it ships at 19200 with j1 and j2 on the back set.
    I tried it at 9600 though, with no luck.

    the one that you are thinking of is the 2x12 i believe. I did quite a bit of reading on several other models to try and get an idea of what I might be doing wrong.

    I have the bs2 on the homework board, but I also have a boebot an extra board that I can put the javalin or the bs2p mc on....so I've got optoins [noparse]:)[/noparse]

    -Mark
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-02-02 13:44
    So, what about this "serout1,32" stuff?· Was that a typo?

    Also, I think the LCD, on power-up, displays an initialization screen.· Does it do that much?

    Can you U/L a sketch of your set-up?· If you are running the STAMP and the LCD from·separate supplies (batteries), their circuit ground/s need to be joined.

    One more thing, reading the PBASIC Help, I think the highest baudmode for a BS2 (i.e. the HomeWork Board) is 9600 [noparse][[/noparse] "84" ].

    Post Edited (PJ Allen) : 2/2/2006 1:47:23 PM GMT
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-02 15:37
    PJ Allen,

    ·· BS can transmit at higher baud rates.· Our LCD Displays use 19,200 bps and our PSC uses 38,400 bps.· It's receiving sustained data at anything higher than 9600 bps that poses a problem due to no FIFO Buffer.· Even then flow control can help curb that issue.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-02-02 18:55
    Well, Glory-oskey, anyways.

    I know that one can calculate a baudmode, but I was just going with the info presented in the tables in the PBASIC Help for SERIN/OUT.
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-02 19:21
    PJ,

    I had actually tried to use 84 with no luck at all. I was initially trying 19200 [noparse][[/noparse]32]as this was the default and from what I had read, should have worked. I had tried anotherbaudmode, but nothing so far. I was going to knock it down to 2400 just for S&G....

    I do have the init screen come up as I had mentioned, but thats it, it just stays with that.

    as far as the setup, it's running from the power supplied on the board and rx on the lcd is connected to pin 0.
    I set this up per spec that was in the erreta
    http://www.parallax.com/dl/docs/prod/audiovis/30058Errata.pdf
    it really doesn't get much simpler than this.....
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-02-02 21:17
    · Well, not too long ago another member posted of his having trouble/s with his Matrix Orbital LCD --
    http://forums.parallax.com/showthread.php?p=566111

    · His was not unlike your situation.· All of a sudden, it turned around (go figure.)· Maybe take a look at that and the link that the Matrix Orbital guy himself chimed in with.

    · I ordinarily don't know what level of proficiency a Poster has (sometimes it's a 20 yr.+ BSEE needing a clue or one of the·bot-boys, to cite two extremes.)·

    · Just trying to help.

    · Hopefully·one of the Principals has a better idea.
    ·
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-02 22:27
    Thanks, PJ,

    In his post it seems that his was displaying trash info, which mine is just displaying the startup screen.
    I am using the homework board, but I guess I could try using the boe that I have.

    As far as my level with this stuff, I'm pretty new, although I do have quite a few goodies... I have the "what is a MC" , a boe bot(not built), an extra boe board + 2 extra mc's(a javelin and a bs2p24) to play with, and various components, ic's, caps, res's, and the such. I bought this stuff initially for my own tinkering around, but now I'm trying to see if my nephew is interested in this as well. I figure it would be a good thing to learn and might get him interested in a robot club at his school....
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-03 00:52
    Hello,

    ·· Your mention of having a H/W Board reminded me that I think we've seen this before.· The modified Matrix Orbital Displays don't seem to work properly when there is a 220 ohm resistor in line with the signal line, as is the case on the H/W Board.· What's happening is the line is not swinging high enough in voltage sufficiently for this display.· You may need to use a buffer inline unless you have a BOE or another development board without the protection resistors.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-03 01:35
    Thanks for the info on that chris!

    I'll pull out hte boe and test it out tonight. I'll let ya know what the outcome is.


    -Mark
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-03 17:11
    Awesome, it worked like a charm after plugging it into the BOE and bs2!!!

    So this LCD doesn't work too well with the homework board.

    Maybe this should be a technote somewhere in the manual or on the page where it's sold as I couldn't find any notes on this when searching???

    Thanks for the help!!
    -Mark
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-02-03 20:03
    I bet it'll work if you put an inverter in between (two resistors and an NPN) and·select an·"inverted"· baudmode.· [noparse][[/noparse] Just a suggestion. ]
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-04 02:51
    not sure how I'd do that, like I said, I'm pretty new to this...links or a diagram would be helpful!!

    Thanks,
    Mark
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-02-04 03:09
    voodoofish saith...
    ... or a diagram would be helpful!!
    OK -- here you go.

    I think you're using a True baudmode, with this you'll have to switch to an Inverted baudmode.· If I knew which speed you are using now I'd give you that detail.

    (The transistor is a 2N3904, I think all of these parts are in the WAM-HWB kit.)

    I wrote "VCC" on the schematic, but it should be VDD -- the +5V.

    Post Edited (PJ Allen) : 2/4/2006 3:16:59 AM GMT
    inv_lcd.jpg
    430 x 414 - 31K
  • ChetChet Posts: 150
    edited 2006-02-04 03:34
    If I am not mistaking, the early HW board had current limiting resistors in lines to the header connection.· Maybe that explains the difference of the two board results. (micht be a victum of old age...)

    Chet
  • voodoofishvoodoofish Posts: 67
    edited 2006-02-04 04:59
    Hiya Chet,

    I think thats the conclusion that chris noted. I'm glad it works though.

    PJ, I"ll try out your little inverter thing at some point this weekend. Thanks for the diagram!! [noparse]:)[/noparse]

    -Mark
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