Writing Variables to Serial LCDs

Velocit

This will hopefully be a pretty easy question for most of you to answer...

I have the SX Tech Board with SX28AC/DP chip and a Parallax 2x16 Serial LCD. I can display text just fine, but I cannot for the life of me figure out how to print a numeric value from a variable to the LCD. Does anyone have a code snippet or explanation as to how to do this? I appreciate your help very much.

I studied the RFID Reader and Serial LCD sample projects in the Help section, but I still can't quite figure it out. I've also looked at the sample programs for both SX/B and BS2 for the serial LCD, but displaying numeric variables doesn't seem to be as straightforward in SX/B as it is in PBASIC. Thanks!

Sparks-R-Fun

Velocit

Velocit

Thanks so much for the link. I didn't realize converting a binary to BCD would be so complicated. I think I understand the code, I'm just not sure how to implement it properly... I just want to transmit the number using the SEROUT command.

JonnyMac

I think this function will work to replicate the DIG operator that is often used in PBASIC programs.

' Use: result = DIG value, position
' -- "value" is byte or word
' -- "position" is byte, 0 to 4

DIG:
  IF __PARAMCNT = 2 THEN
    tmpW1 = __PARAM1
    tmpB1 = __PARAM2
  ELSE
    tmpW1 = __WPARAM12
    tmpB1 = __PARAM3
  ENDIF

  tmpB2 = 0
  IF tmpB1 < 5 THEN
    LOOKUP tmpB1, 1, 10, 100, 1000, 10000, tmpW2
    tmpW1 = tmpW1 / tmpW2        
    tmpW1 = tmpW1 // 10
    tmpB2 = tmpW1_LSB
  ENDIF

  RETURN tmpB2

Declare it with:

DIG        FUNC    1, 2, 3

william chan

Maybe you could try our iLCD product, another shameless serial LCD copycat based on the SX.
It accepts a byte sized numeric variable and directly displays it as a HEX or a DECIMAL STRING.
This saves code space on your main processor.

For example, to display a variable temp, just output using SEROUT ESC, "N", temp
and the value of temp will magically appear on the screen.

See www.fd.com.my/products/ilcd/ilcd.php

Good Luck.

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www.fd.com.my
www.mercedes.com.my

Velocit

Jonny,

I really appreciate the code snippet, but I still can't seem to get it to work. I copied the code verbatim and defined the variables and function as necessary. The output is still incomprehensible on the LCD screen. Is the position value just another working variable? Here's how I'm using the code as of now...

  f = 3 
  i = DIG f, d
  LCD_OUT i

Where...

f        VAR    Byte
i        VAR    Byte
d        VAR    Byte

JonnyMac

Sorry, you have to convert the digit value (0..9) to ASCII for the LCD; it's easy, just add 48 ("0") to the digit value and that should do the trick. I was just showing a function that duplicated a PBASIC operator; I should have provided a bit more detail for your application. Do this:

  myDigit = DIG theValue, digPos
  myDigit = myDigit + "0"
  LCD_OUT myDigit

The second line converts the digit from a number to the correct ASCII code.

Velocit

Excellent! Thank you so much, I really appreciate your help.