Displaying calculated numbers on Parallax parallel LCD

studebaker1925 · 2012-03-04 02:41

I am using the Parallax Experiment kit which comes with a parallel (not serial) LCD and the BS2. I am measuring resistance of a pot using the supplied 555 oscillator chip with the result stored as a Word variable (let's call it ResistanceValue). I view the result using DEBUG as a decimal (DEC) with 4 digits using DEBUG CRSRXY, 13, 2, DEC ResistanceValue, CLREOL. I would like to display this four digit value on the parallel LCD. I have no problem loading characters from a string (from the EEProm) such as "This is the resistance=" but have yet to work out how to add the number generated from the resistance.

:blank: Steve

Mike G · 2012-03-04 04:59

Welcome studebaker1925...

This is not the most elegant method for converting an integer to a character byte array (string) but it works and should give you some ideas.

' {$STAMP BS2p}
' {$PBASIC 2.5}

' VARs
number    VAR   Word
char      VAR   Byte(4)

'Init
number = 1234


Main:
  ' Get the individual numbers
  char(3) = number // 10
  number = number - char(3)

  char(2) = number // 100
  number = number - char(1)
  char(2) = char(2) / 10

  char(1) = number // 1000
  number = number - char(2)
  char(1) = char(1) / 100

  char(0) = number / 1000

  GOSUB PrintHex

  'Conver the numbers to ASCII
  char(0) = char(0) + $30
  char(1) = char(1) + $30
  char(2) = char(2) + $30
  char(3) = char(3) + $30

  GOSUB PrintHex
  GOSUB Print
END

PrintHex:
  DEBUG HEX ?char(0), HEX ?char(1), HEX ?char(2), HEX ?char(3)
  RETURN

Print:
  DEBUG STR char \4
  RETURN

studebaker1925 · 2012-03-04 06:26

Thanks. I had thoughts on the same lines and came up with this (not the complete code):

MsgNums DATA "0123456789" ' store number characters in array

...Extract_Digits_from_number:

R1=Number//1000
R2=R1//100
R3=R2//10
R4=R3
R3=R2/10
R2=R1/100
R1=Number/1000

...then

READ (MsgNums + R1), char ' read a character from MsgNums
GOSUB LCD_Out ' write character at next cursor location
READ (MsgNums + R2), char ' read a character from MsgNums
GOSUB LCD_Out ' write character at next cursor location
READ (MsgNums + R3), char ' read a character from MsgNums
GOSUB LCD_Out ' write character at next cursor location
READ (MsgNums + R4), char ' read a character from MsgNums
GOSUB LCD_Out ' write character at next cursor location

Tracy Allen · 2012-03-04 12:09

Also take a look at the Stamps DIG operator.
X=12345

X DIG 4 returns the 10^4 decimal digit (1 in this case)
X DIG 0 returns the 10^0 decimal digit (5 in this case)

add 48 to that and you have the numeric ascii code to send to the LCD
X DIG 4 + 48

You can loop through the digits and suppress leading zeros or turn them into spaces if you want.

Displaying calculated numbers on Parallax parallel LCD

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