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Using a BOE with a handyboard LCD — Parallax Forums

Using a BOE with a handyboard LCD

CheetoCheeto Posts: 19
edited 2006-06-02 19:46 in Robotics
I found an old Handyboard setup at school, I ordered the MAX232 to build a programmer for it and I still can't get it to talk to the computer. So now I am looking to scrap it for parts, it has a nice 2 line LCD display that would be cool if I could output stuff to it from the BOE.

The LCD connects to the upper left connector strip next to the speaker, unfortently I can't much info on the LCD board itself. I belive these are the data sheets for it
rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=67&M=LCM-S01602DTR/A

Just on a long shot if anyone has experince with the www.handyboard.com and can tell me some simple things to test on why my DL program won't work with it please speak up =)

hb121silk.gif

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-05-30 20:26
    I figure the LCD that plugs into U4 is likely a "parallel" LCD (HD44780) -- and information on interfacing that with a STAMP abounds in previous posts (do a little Search) and in the Downloads section over at www.parallax.com
  • CheetoCheeto Posts: 19
    edited 2006-05-31 00:50
    That looks like exactly what I need, while I can't find mention of the LCD being a HD44780 compliant i guess ? I am going to assume it is since all the pin outs match. Now to try and see if I blow up my board =)

    edit: found a webpage saying it was based on the HD44780

    Post Edited (Cheeto) : 5/31/2006 12:57:30 AM GMT
  • CheetoCheeto Posts: 19
    edited 2006-05-31 21:35
    Got it working, after I figured out the contrast control on it. Thanks for the help
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-05-31 22:24
    Real Good.
    As a "parallel" LCD, it takes up several I/Os.· Look into getting a "serial back-pack" for it, then you'll only take up 1 I/O pin.· This also saves Big-Time on programming/program space as you send the characters, etc.·as SEROUT statements and don't have to do all of that initialization jazz and the rest of it.

    Post Edit -- http://www.phanderson.com/lcd106/lcd107.html
    ·
  • CheetoCheeto Posts: 19
    edited 2006-05-31 23:21
    I was thinking of getting a serial LCD, but this one was free. It takes up 7 pins but I think I can use 6 since I am fairly certain I can tie the R/W pin to high since I am only writing to the LCD.

    On that page you linked do I need both the LCD and the chip ? I am assuming I do, it looks like its serial input the chip and the chip controls the LCD

    Also wish the HD44780 used the standard ASCII table =(
  • ForrestForrest Posts: 1,341
    edited 2006-05-31 23:52
    Phanderson's #107 or #117 serial LCD controller chip works with ANY HD44780 LCD, including the one you already have. But Phanderson doesn't offer a board to plug the chip into - that's why the picture at the bottom of the page shows the controller and circuit assembled on a breadboard. I suggest getting the K107 board/kit from www.wulfden.org/k107/index.shtml. The K107 board/kit uses Phanderson's #107 or #117 controller and it works great - bought one for myself.
  • CheetoCheeto Posts: 19
    edited 2006-06-01 00:03
    I looked through the page and am thinking of getting the LCD115 Blue/White for 39.95
    www.phanderson.com/lcd106/lcd115.html

    Would I control this from the stamp just using serout with the $ sign commands the webpage list ?
  • RGuyserRGuyser Posts: 90
    edited 2006-06-02 09:13
    cheeto,

    this document[noparse]:http:[/noparse]//www.parallax.com/dl/docs/prod/audiovis/lcd2x16par.pdf

    describes how to use a 14-pin parallel LCD. It uses 7 IO pins, but you can still use them for interface switches as the LCD has abugger which holds whatever you last sent it until you tell it to clear.

    I am currently trying to figure out how to actually use this code to create a simple interface which uses 4 buttons, and the LCD...

    It seems we might have to constantly load stuff in and out of the EEPROM as some sort of buffer. Ive got it working with a preset eeprom entry and a known word length... The next step is to learn how to repeatedly load it with new data and identify the word length..
  • RGuyserRGuyser Posts: 90
    edited 2006-06-02 09:15
    also, i think on ebay you can get rs232 to paralel LCD chips for ~7$ shipped. I am not sure what other products cost.
  • CheetoCheeto Posts: 19
    edited 2006-06-02 19:46
    I got the LCD working with the 4 buttons on the i/o lines, it's neat but I think I would rather just have a serial LCD, dont have to worry about intilizing and all that jazz
    http://www.parallax.com/dl/docs/prod/appmod/LcdTerminal.pdf

    There is a schematic at the end of the document, and running the example code it works just like it says it should.
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