Hey group,
I have been working on this code to display big digits on a 4 x 20 serial LCD. The one I am using is from MElabs.
I bet this code would work on other serial and non-serial LCD's.
I found the basis for theis code in this thread... http://www.picbasic.co.uk/forum/showthread.php?t=5443
Thanks mister_e !! and others who contributed.
I took that code and made it work for my needs. Some of the things I changed from mister_e's version...
cleaned up the font data
eliminated one of the custom characters that was un-needed (the solid block, which $FF will do)
added another custom character (upper DOT that could be used for a colon in a time display, etc
made the code only update the digit that changed to the LCD. Instead of clearing and re-writing the whole LCD every time
other code improvements, variable name changes, and LOTS of comments.
I hope someone else can use it and have FUN with it.
I have only tested it with a 16F690
enjoy!!
Code:' 16F690
'****************************************************************
'* Name : UNTITLED.BAS *
'* Author : [select VIEW...EDITOR OPTIONS] *
'* Notice : Copyright (c) 2007 [select VIEW...EDITOR OPTIONS] *
'* : All Rights Reserved *
'* Date : 11/25/2007 *
'* Version : 1.0 *
'* Notes : *
'* : *
'****************************************************************
' ---------- [ CONFIGURATION BITS ]---------------------
' The following config for 16F1828 may need some work and the various
' ADCON's, CMCON0, CMCON1, ANSEL, ANSELH, etc. etc. will need to be
' reviewed and corrected for the 16f1828.
' THE CODE HAS ONLY BEEN TESTED ON A 16F690
#IF __PROCESSOR__ = "16F1828"
#CONFIG
__CONFIG _CONFIG1, _FOSC_INTOSC & _WDTE_ON & _PWRTE_OFF & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOREN_OFF & _CLKOUTEN_OFF & _IESO_OFF & _FCMEN_OFF
__CONFIG _CONFIG2, _WRT_OFF & _PLLEN_OFF & _STVREN_OFF & _BORV_25 & _LVP_OFF
#endconfig
#ELSE
#IF __PROCESSOR__ = "16F690"
#CONFIG
__CONFIG _INTRC_OSC_NOCLKOUT & _WDT_ON & _PWRTE_OFF & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOD_OFF & _IESO_OFF & _FCMEN_OFF
#endconfig
#ELSE
#ERROR "Program does not support " + __PROCESSOR__
#ENDIF
#ENDIF
#msg "compiling for target " + __PROCESSOR__
' DEFINE LCD_DREG PORTD ' LCD data port
' DEFINE LCD_DBIT 4 ' LCD data starting bit 0 or 4
' DEFINE LCD_RSREG PORTD ' LCD register select port
' DEFINE LCD_RSBIT 2 ' LCD register select bit
' DEFINE LCD_EREG PORTD ' LCD enable port
' DEFINE LCD_EBIT 3 ' LCD enable bit
' DEFINE LCD_BITS 4 ' LCD bus size 4 or 8
' DEFINE LCD_LINES 4 ' Number lines on LCD
' DEFINE LCD_COMMANDUS 2000 ' Command delay time in us
' DEFINE LCD_DATAUS 50 ' Data delay time in us
' -----[ I/O CONFIGURATION ]-------------------------------------------------
DEFINE ADC_BITS 8
DEFINE ADC_CLOCK 3 `
DEFINE ADC_SAMPLEUS 50
DEFINE OSC 4
TRISA = %00111111 'PortA 2 A/D input
TRISB = %00110000 'PortB 6,7 out to LCD 4,5 in from buttons
TRISC = %00000000 'PortC all output 8 bit binary display
ADCON0 = %00001001 'left justified 0xxxxxxx or right justified 1xxxxxxx
'vdd x0xxxxxx
'AN2 xx0010xx through AN11 xx1011xx
'go/done ------x- don't care
'ADC enabled xxxxxxx1
ADCON1 = %00010000 'fOSC/8 % x001xxxx
ANSEL = %00000100 'and set AN2 pin to Analog
ANSELH = %00000000
CM1CON0 = 0 'turn off the comparator 1
CM2CON0 = 0 'turn off the comparator 2
'================================================================
' ============[ Variables for LCD routines only ] ==============
'================================================================
Pattern VAR WORD[11]
Line VAR BYTE[4]
Value VAR WORD
Value = 0
Row VAR BYTE
Col VAR BYTE
block VAR BYTE
Char1 VAR BYTE
Char2 VAR BYTE
Char3 VAR BYTE
Char4 VAR BYTE
Last0 VAR BYTE
Last1 VAR BYTE
Last2 VAR BYTE
Last3 VAR BYTE
Digit VAR BYTE
Digit=0
Last0=1 'these "LAST" variables are used to determine if
Last1=1 ' each of the digits hase changed and the LCD needs
Last2=1 ' updating. They are initialised to 1 and assume
Last3=1 ' the starting "Value" variable will be 0000
' -----[ Constants ]-------------------------------------------------------
Cmd CON $FE 'LCD prefix for Command
Clr CON 1 'LCD CLEAR SCREEN
Hm CON 2 'LCD HOME COMMAND
Line[0]=$80 ' LCD line 1
Line[1]=$C0 ' LCD line 2
Line[2]=$94 ' LCD line 3
Line[3]=$D4 ' LCD line 4
'==========================================================
'=== Main program variables not part of LCD routines =====
'=== Your program variables go here =====
'==========================================================
x VAR WORD
'===========================================================
' -----[ Font definitions -->> PIC EEprom Data ]------------
Zero DATA 5 ,0 ,0 ,4
DATA $FF,$20,$20,$FF
DATA $FF,$20,$20,$FF
DATA 2 ,1 ,1 ,3
One DATA $20,5 ,$ff,$20
DATA $20,$20,$ff,$20
DATA $20,$20,$ff,$20
DATA $20,$20,$ff,$20
Two DATA 0 ,0 ,0 ,4
DATA $20,$20,$20,$ff
DATA 5 ,0 ,0 ,0
DATA $ff,1 ,1 ,1
Three DATA 0 ,0 ,0 ,4
DATA $20,$20,$20,$ff
DATA $20,0 ,0 ,$ff
DATA 1 ,1 ,1 ,3
Four DATA $ff,$20,$20,$FF
DATA $ff,$20,$20,$ff
DATA 0 ,0 ,0 ,$ff
DATA $20,$20,$20,$ff
Five DATA $FF,0 ,0 ,0
DATA $ff,$20,$20,$20
DATA 0 ,0 ,0 ,4
DATA 1 ,1 ,1 ,3
Six DATA 5 ,0 ,0 ,$20
DATA $ff,$20,$20,$20
DATA $ff,0 ,0 ,4
DATA 2 ,1 ,1 ,3
Seven DATA 0 ,0 ,0 ,4
DATA $20,$20,$20,$ff
DATA $20,$20,$20,$ff
DATA $20,$20,$20,$ff
Eight DATA 5 ,0 ,0 ,4
DATA 2 ,1 ,1 ,3
DATA 5 ,0 ,0 ,4
DATA 2 ,1 ,1 ,3
Nine DATA 5 ,0 ,0 ,4
DATA 2 ,1 ,1 ,$ff
DATA $20,$20,$20,$ff
DATA $20,1 ,1 ,3
Dot DATA $20,$20,$20,$20
DATA $20,$20,$20,$20
DATA $20,$20,$20,$20
DATA $20, 7,$20,$20
Pattern[0]=Zero
Pattern[1]=One
Pattern[2]=Two
Pattern[3]=Three
Pattern[4]=Four
Pattern[5]=Five
Pattern[6]=Six
Pattern[7]=Seven
Pattern[8]=Eight
Pattern[9]=Nine
Pattern[10]=Dot
' -----[ Custom LCD characters used to create BIG fonts ]-----------------------
DumpCustChar:
Row=0
PAUSE 500
REPEAT ' Define custom characters
LOOKUP Row,[_
Cmd,064,31,31,31,31,00,00,00,00,_ ; Cust Char #0 upper half
Cmd,072,00,00,00,00,31,31,31,31,_ ; Cust Char #1 lower half
Cmd,080,31,31,31,15,07,03,01,00,_ ; Cust Char #2 \^ upper
Cmd,088,31,31,31,30,28,24,16,00,_ ; Cust Char #3 /^ upper
Cmd,096,00,16,24,28,30,31,31,31,_ ; Cust Char #4 \ lower
Cmd,104,00,01,03,07,15,31,31,31,_ ; Cust Char #5 / lower
Cmd,112,14,31,31,31,14,00,00,00,_ ; Cust Char #6 upper dot
Cmd,120,00,00,00,14,31,31,31,14],Char1 ; Cust Char #7 lower dot
SEROUT2 PortB.7, 16468, [Char1] 'Store custom char in LCD mem
Row=Row+1
UNTIL Row=80
' -----[ Initialization ]--------------------------------------------------
PAUSE 500
SEROUT2 PortB.7, 16468, [$1b,$2a,128] 'LCD backlight half on
SEROUT2 PortB.7, 16468, [Cmd,Clr] 'clear LCD
'======================================================
'======================================================
' This is where your main program goes... what ever you want to do
' and what ever you want to display on the LCD using big digits.
' From this section you GOSUB LCDupdat with your 1 to 4 digit number
' loaded into the variable called "Value"
' That number can be a temperature, counter, A/D value, voltage etc.
' NOTE: You may need to create other Letter Font definitions
' in order to display your data. (-,+,F, etc.)
'---------------------------------------------------------------
Main:
FOR x=0 TO 9999
Value = x
GOSUB LCDupdate
PAUSE 100
NEXT x
GOTO Main
END
'=========================================================================
'======= SubRoutine determine which LCD digit needs updating ==========
'=========================================================================
LCDupdate: 'Col is the LCD column to write to from L to R
LL: Col=0 ' Left most digit
Digit=Value DIG 3
IF Last3 = Digit THEN LC 'This digit didn't change so skip it
GOSUB LCDwrite 'Digit did change so update display
Last3=Digit
LC: Col=5 ' Left-of-Center digit
Digit = Value dig 2
IF Last2 = Digit THEN RC 'This digit didn't change so skip it
GOSUB LCDwrite 'Digit did change so update dispay
Last2=Digit
RC: Col=10 ' Right-of-center digit
Digit = Value dig 1
IF Last1 = Digit THEN RR 'This digit didn't change so skip it
GOSUB LCDwrite 'Digit did change so update display
Last1=Digit
RR: Col=15 ' Right most digit
Digit=Value DIG 0
IF Last0 = Digit THEN done 'This digit didn't change so skip it
GOSUB LCDwrite 'Digit did change so update display
Last0=Digit
done:
RETURN
'=======================================================================
'================ SubRoutine to Write to the LCD =====================
'=======================================================================
LCDwrite: 'this will erase the digit before writing the new one
FOR Row = 0 TO 3
SEROUT2 PortB.7, 16468,[Cmd,Line[Row]+Col] 'move cursor into position
SEROUT2 PortB.7, 16468,[$20,$20,$20,$20] 'erase line
NEXT Row
' pause 100 'pause will make display look more animated but will slow it down
'-------------------------------------------------------------------
DigitWrite: ' Now write the digit
FOR Row=0 TO 3
LOOKUP Row,[0,4,8,12],block
SEROUT2 PortB.7, 16468,[Cmd,Line[Row]+Col] 'move cursor into position
READ Pattern[Digit]+block,Char1,Char2,Char3,Char4 'read font data
SEROUT2 PortB.7, 16468,[Char1,Char2,Char3,Char4] 'write character data
NEXT Row
RETURN
