Big Digits on 4x20 LCD


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  1. #1
    Join Date
    Oct 2009
    Location
    Utah, USA
    Posts
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    Default Big Digits on 4x20 LCD

    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
    Dwight
    These PIC's are like intricate puzzles just waiting for one to discover their secrets and MASTER their capabilities.

  2. #2
    Join Date
    Oct 2009
    Location
    Utah, USA
    Posts
    427

    Default Re: Big Digits on 4x20 LCD

    I wish the code formatting would transfer when posing in a "CODE" window.
    It seems all the tabs and spaces get lost.

    Here is the .pbp file which should be formatted better for reading and editing...
    You may need to delete the .txt extension and keep the .pbp extension.

    16f690 LCD_BigDigits.pbp.txt
    Last edited by Heckler; - 19th February 2013 at 01:07.
    Dwight
    These PIC's are like intricate puzzles just waiting for one to discover their secrets and MASTER their capabilities.

  3. #3
    Join Date
    Oct 2009
    Location
    Utah, USA
    Posts
    427

    Default Re: Big Digits on 4x20 LCD

    Here is a photo of the display...

    Name:  2013-02-18 20.34.48.jpg
Views: 3061
Size:  434.9 KB
    Dwight
    These PIC's are like intricate puzzles just waiting for one to discover their secrets and MASTER their capabilities.

  4. #4
    Join Date
    May 2006
    Location
    Del Rio, TX, USA
    Posts
    343

    Default Re: Big Digits on 4x20 LCD

    Looks good!

  5. #5
    Join Date
    Jun 2013
    Posts
    17

    Default Re: Big Digits on 4x20 LCD

    Hello Heckler,

    Thank you in advance for sharing this valuable routine.

    I have some questions:


    Would you please let me know if I want to add a point between 1st and 2nd digits? I'd like to show pressure by this method, so would you please modify your source code for this purpose? And how about the "R/w" pin of LCD? Can you please draw a simple diagram on and attach here? Honestly, I cannot understand how you would write your new-design characters inside LCD,

    I would deeply appreciate you, if you enforce the answer please.

    Kind regards,

    Andy

  6. #6
    Join Date
    Oct 2009
    Location
    Utah, USA
    Posts
    427

    Default Re: Big Digits on 4x20 LCD

    Hi Andy,

    Well, as you can see it has been a full year since I posted that code.
    I would have to spend several hours studying it to make suggestions that you request.

    Have you tried to load it up and see if you can make it work as is? Just as a starting point?
    As to your question about the R/W pin of the lcd... I was using an LCD with Serial backpack.
    If you don't know what that is take a look here...
    http://store.melabs.com/cat/displays.html
    So if you go that route then you will not have to worry about the R/w line.
    They sell just the backpack if you have your own lcd.
    these are VERY handy for prototyping and testing code because they can be written to via a SEROUT command.

    It should work with a regular LCD also just follow the example in the PBP manual as a starting point.

    The real way to learn is to study and try and modify a small portion of the code or the font data table and see what it does.

    They sell just the backpack if you have your own lcd.
    these are VERY handy for prototyping and testing code because they can be written to via a SEROUT command.

    My suggestion is that you load the code up in Microcode studio... or even better is the IDE called FineLine as it allows you to visualize the various subroutines and loops very well.

    Give the code a try and then ask questions.

    It is very easy to just copy the code above and past it into your IDE and study it there. Then it will be color coded and easier to read.

    If you havent tried FineLine then give it a try.

    Just search the forum here for FineLine as the author is a regular here and you should be able to find a link to down load it.

    good luck
    Last edited by Heckler; - 27th February 2014 at 04:10.
    Dwight
    These PIC's are like intricate puzzles just waiting for one to discover their secrets and MASTER their capabilities.

  7. #7
    Join Date
    Jun 2013
    Posts
    17

    Default Re: Big Digits on 4x20 LCD

    Quote Originally Posted by Heckler View Post
    I would have to spend several hours studying it to make suggestions that you request.

    ... I was using an LCD with Serial backpack.
    Hi Heckler,

    I hope it finds you well.

    Thank you for your kind replying here.

    I really appreciate you in advance for your support.

    My suggesstion is to modify your written routine under my Microcode studio and just assign a pin for "R/w". and using LCDIN command for writing in LCD's RAM and so on. Because I should work with usual LCDs. I think I should all these two headers

    DEFINE LCD_RWREG PORTE ' LCD read/write pin port
    DEFINE LCD_RWBIT 2 ' LCD read/write pin bit
    What do you think Sir?

    After I received your help, if my suggestion be right, it seems, it would be easy to fix this section. But now, I am hardly busy at something else, a damn PID routine for pressure control. and honestly I cannot focus on anything else. My mind is 100% busy

    May I very kindly ask you twice to take a look again at your valuable work and give me some points/remedy for implementing a dot, between 1st and 2nd numbers (from left side)?

    I really appreciate you in advance for your support.

    I would never forget your kind help.

    Best regards,

    Andy

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