Propeller writing to SparkFun Serial LCD

StevenG · 2010-07-01 15:22

I have the Propeller Servo Controller USB and a SparkFun Serial LCD. I was wondering if anyone has some example code for writing text/commands to the LCD. I've played around with it a little but got frustrated. Any help would be much appreciated.

Propeller Servo Controller USB
http://www.parallax.com/Store/Microcontrollers/PropellerDevelopmentBoards/tabid/514/CategoryID/73/List/0/SortField/0/Level/a/ProductID/595/Default.aspx

SparkFun Serial LCD
http://www.sparkfun.com/commerce/product_info.php?products_id=9395

StevenG · 2010-07-02 18:03

Ok. I've written a small program to write ASCII characters to the LCD but I can't seem to get any of the LCD commands to work. They almost always come up as two vertical lines in one character space. I have attached the code I am using.

The code should turn on the Blinking Box Cursor and then write "Hello World!" to the LCD. Instead it prints "||Hello World!".

humm.........

CON

  baud            = 9600                                          ' baud rate
  pin             = 0                                             ' tx pin
  _clkmode        = xtal1 + pll16x
  _xinfreq        = 5_000_000

  
  LCD_BKSPC     = $10                                   ' move cursor left
  LCD_RT        = $14                                   ' move cursor right
  LCD_CLS       = $01                                   ' clear LCD (follow with 5 ms delay)
  LCD_SET       = $7C                                   ' LCD Set Parameter
    LCD_BL1     = 128                                   ' Set backlight to 0%
    LCD_BL2     = 140                                   ' Set backlight to 40%
    LCD_BL3     = 150                                   ' Set backlight to 73%
    LCD_BL4     = 157                                   ' Set backlight to 100%

    LCD_SST     = $09                                   ' Toggle Splash Screen
    LCD_SSS     = $0A                                   ' Save current screen to splash screen

    LCD_24      = $4B                                   ' Set Baud to 2400
    LCD_48      = $4C                                   ' Set Baud to 4800                        
    LCD_96      = $4D                                   ' Set Baud to 9600
    LCD_144     = $4E                                   ' Set Baud to 14400
    LCD_192     = $4F                                   ' Set Baud to 19200
    LCD_384     = $50                                   ' Set Baud to 38400
    
  LCD_OFF       = $08                                   ' LCD visual off
  LCD_ON        = $0C                                   ' LCD visual on
  LCD_CRON      = $0E                                   ' LCD cursor on
  LCD_CROFF     = $0C                                   ' LCD cursor off
  LCD_BXON      = $0D                                   ' Blinking box cursor on
  LCD_SR        = $1C                                   ' LCD scroll right
  LCD_SL        = $08                                   ' LCD scroll left
  LCD_CRP       = $80                                   ' LCD set cursor position + position 
  
OBJ

  serial : "simple_serial"                              ' bit-bang serial driver

PUB init | Temp

  waitcnt(clkfreq / 4_000 + cnt)  
  serial.init(-1, pin, baud)
  waitcnt(clkfreq / 200 + cnt)
  serial.tx(LCD_BXON)
  waitcnt(clkfreq / 200_000 + cnt)
  serial.str(string("Hello World!"))

Harley · 2010-07-02 18:09

One thing I note is there is no 'repeat'. Your code just runs to the last instruction ONCE.

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Harley Shanko

grouchy · 2010-07-03 01:46

try this, what I use for my sparkfun serial lcd.

note that if your using the 3.3v lcd, it sometimes gets confused at power up if the usb plug is connected (on the demo board). To reset the lcd, remove the usb plug as well as power down the demo board.

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Rudy's CNC Freeware·· http://www.enter.net/~schleinkofer

mpark · 2010-07-03 15:35

Grouchy, cute use of lookdown!

StevenG, you have to send $fe before sending a command byte.

StevenG · 2010-07-03 16:23

Ya I forgot about the whole command byte thing. The $FE common byte doesn't work for the backlight and some other commands. You have to send the $7C command for those. It takes a little trial and error to figure out which one requires what. Thanks a lot Grouchy that helped a ton!!!

Propeller writing to SparkFun Serial LCD

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