SSD1306 OLED (72x40) I2C display from scratch

**Ioannis** · - 15th November 2023, 16:58

These LCD's are difficult to use. Indeed there are too many parameters to set and also you have to design the characters to display.

The good thing is that you have flexibility in designing the characters, the bad is that you have to do it!

The good member Richard has done much of the dirty work to use these LCD's and gave us the libraries. But you have to do your part too, especially if you have different LCD. You need to adapt to the dimensions of the screen, design your graphics etc...

Powering up the display may not light any LED's and display nothing. All are software controlled.

I tried an 0.9" LCD and with the support of the Richard managed to display text in various sizes. But I admit I have not fully mastered the beast.

Ioannis

**richard** · - 15th November 2023, 23:49

The latest version of the include is on post #90 of the link posted by ionnis reposted here for your convenience

this display is not something you can sneak up on easily , you really need a 100% solution before you can get anywhere

your 42x40 version will very likely need a few tweaks to match the way the oled array has been mapped onto the segment/com pins
and represented on the graphic memory overlay of the driver chip, i don't have one to experiment with

there is an alternative version here for p18 chips only that is more versatile, it would still need the same tweaks too
https://www.picbasic.co.uk/forum/sho...lays-with-PBP3

the init routine is fairly well commented if you read it in conjunction with the ssd1306 data sheet

Code:

'****************************************************************'*  Name    : ssd1306_I2C.INC                                   *
'*  Author  : richard                                           *
'*  Notice  :                                                   *
'*          :                                                   *
'*  Date    : 8/2/2022                                          *
'*  Version : 1.2                                               *
'*                                                              *
'*                                                              *
'*  Notes   : font address banksel fixed                        *
'*          :FOR pic 16/18       SSD1306                        *
'****************************************************************
 
 goto overglcd
; adjust to suit and  place these in main prg
;use this define for hw i2c 
;#define hwi2c 1 
;#DEFINE PIC16 1    ;IF PIC 16 USED  [USE PIC16 FONT TOO}
' ssdheight con 7       ; 7 = 8 PAGES  64*128 ,  3 = 4 pages 32*128
' ssdwidth  con 127     ; 128 PIXELS WIDE
' SCL var PortC.3       ' I2C Clock
' SDA var PortC.4       ' I2C Data
' sdd1306_addr con $78
 
 USERCOMMAND "GLCDC"     ; X,Y,CHR  0 <  X < 127  ,   0 <  Y < 7    31 < CHR > 127  
 USERCOMMAND "GLCD_CLR"  ;clear area x,y,W,H    
 USERCOMMAND "GLCDSTR"   ;STRING @ X,Y  or   Constant String
 USERCOMMAND "GLCDDHL"   ; x,y,L ,bit-patten
 USERCOMMAND "GLCDDVL"   ; x,y,H
 USERCOMMAND "SSDC"      ;cmd BYTE TO SSD1306
 USERCOMMAND "SSDBM"     ;x,y,w,h,label  


 ASM  
 
 
 ;----------------------VERT LINE------------------------------------        
GLCDDVL?CCC  macro Xin ,Yin , Hin 
    MOVE?CB  Xin ,_gx 
    MOVE?CB  Yin,_gy 
    MOVE?CB  Hin ,_gl 
    L?CALL _xyy
    endm 
       
 ;----------------------HORIZ LINE------------------------------------ 
GLCDDHL?CCCC  macro Xin ,Yin , Win ,Cin
    MOVE?CB  Xin ,_gx 
    MOVE?CB  Yin,_gy 
    MOVE?CB  Win ,_gl
    MOVE?CB  Cin ,_glcdData 
    L?CALL _xyx
    endm  
 
  ;----[const String]---------------------------------------------------------------
GLCDSTR?CCS  macro Xin ,Yin,Cin 
 IFNDEF  TBLPTRL
    local TheString, OverStr ; define local labels so you can call macro multiple times
    goto OverStr ; goto over string stored in FLASH, so processor can't execute that
TheString ;label to get address of your string
    da Cin, 0 ;add string to flash at TheString address and end string with 0
OverStr
    MOVE?CW  TheString, _glcd_bigaddress
    MOVE?CB Xin , _gx
    MOVE?CB Yin , _gy
    L?GOTO  _GlcdUnpackStr
 ELSE  
    local TheString, OverStr ; define local labels so you can call macro multiple times
    goto OverStr ; goto over string stored in FLASH, so processor can't execute that
TheString ;label to get address of your string
    data Cin, 0 ;add string to flash at TheString address and end string with 0
OverStr
    movlw   UPPER TheString
    movwf   TBLPTRU
    movlw   HIGH TheString 
    movwf   TBLPTRH
    movlw   LOW TheString
    movwf   TBLPTRL
    MOVE?CB Xin , _gx
    MOVE?CB Yin , _gy
    L?CALL  GLCD_Cstr_out 
 ENDIF     
    endm  
    
     
SSDBM?CCCCL   macro Xin ,Yin ,Win,Hin,BMin 
 IFNDEF  TBLPTRL
    ERROR BITMAPS ONLY SUPPORTED ON PIC18
 ENDIF
     MOVE?CB Xin , _gx
     MOVE?CB Yin , _gy
     MOVE?CB Hin/8-1 , _gy_
     MOVE?CB Win+Xin-1 , _gx_
     MOVE?CW Win*Hin/8 , _glcd_rad
     banksel   _glcdbm
     movlw low BMin
     movwf _glcdbm
     movlw high BMin
     movwf _glcdbm +1
     BANKSEL 0
     L?CALL  _ssd_bitmap
      endm




 ;----------------------Strings------------------------------------
GLCDSTR?CBB  macro Xin ,Yin ,Bin
    MOVE?CB Xin , _gx
    MOVE?BB Yin , _gy
    MOVE?CB high Bin, FSR1H ;load highbyte 
    MOVE?CB low  Bin, FSR1L ;load low byte
    L?CALL  GLCD_str_out
    endm         
GLCDSTR?CCB  macro Xin ,Yin ,Bin
    MOVE?CB Xin , _gx
    MOVE?CB Yin  ,_gy
    MOVE?CB high (Bin), FSR1H ;load highbyte 
    MOVE?CB low  (Bin), FSR1L ;load low byte
    L?CALL  GLCD_str_out
    endm              
GLCDSTR?BBB  macro Xin ,Yin ,Bin
    MOVE?B  Xin, _gx
    MOVE?B  Yin, _gy
    MOVE?CB high Bin, FSR1H ;load highbyte 
    MOVE?CB low  Bin, FSR1L ;load low byte
    L?CALL  GLCD_str_out
    endm 
GLCDSTR?WBB  macro Xin ,Yin ,Bin
    MOVE?WB Xin, _gx
    MOVE?BB Yin, _gy
    MOVE?CB high Bin, FSR1H ;load highbyte 
    MOVE?CB low  Bin, FSR1L ;load low byte
    L?CALL  GLCD_str_out
    endm  
GLCDSTR?WWB  macro Xin ,Yin ,Bin
    MOVE?WB Xin, _gx
    MOVE?WB Yin, _gy
    MOVE?CB high Bin, FSR1H ;load highbyte 
    MOVE?CB low  Bin, FSR1L ;load low byte
    L?CALL  GLCD_str_out
    endm 
 
 
SSDC?C  macro Cin
    MOVE?CB  Cin , _glcdData
    L?CALL   _cmd_byte
   endm 
SSDC?B  macro Cin
    MOVE?BB  Cin , _glcdData
    L?CALL   _cmd_byte
   endm 


GLCD_CLR? macro
    MOVE?CB  0, _gx 
    MOVE?CB  0, _gy 
    MOVE?CB  _ssdwidth, _gx_ 
    MOVE?CB  _ssdheight, _gy_
    L?CALL   _glcd_clrxy
   endm 


GLCD_CLR?CCCC macro   Xin ,Yin,X1in ,Y1in
    MOVE?CB  Xin, _gx 
    MOVE?CB  Yin, _gy 
    MOVE?CB  X1in, _gx_ 
    MOVE?CB  Y1in, _gy_
    L?CALL   _glcd_clrxy
   endm 
       
 ;----------------------Character @ X,Y ------------------------------------        
GLCDC?BBB  macro Xin ,Yin , Bin
    MOVE?BB  Xin, _gx 
    MOVE?BB  Yin, _gy 
    MOVE?BB  Bin, _glcdCh
    L?CALL   _gcga
    endm    
GLCDC?WBB  macro Xin ,Yin , Bin
    MOVE?WB  Xin, _gx 
    MOVE?BB  Yin, _gy 
    MOVE?BB  Bin, _glcdCh
    L?CALL   _gcga
    endm  
GLCDC?WWB  macro Xin ,Yin , Bin
    MOVE?WB  Xin, _gx 
    MOVE?WB  Yin, _gy 
    MOVE?BB  Bin, _glcdCh
    L?CALL  _gcga
    endm    
        
GLCDC?BBC  macro Xin ,Yin , Cin
    MOVE?BB  Xin, _gx 
    MOVE?BB  Yin, _gy 
    MOVE?CB  Cin ,_glcdCh
    L?CALL   _gcga
    endm   
GLCDC?WBC  macro Xin ,Yin , Cin
    MOVE?WB  Xin, _gx 
    MOVE?BB  Yin, _gy 
    MOVE?CB  Cin ,_glcdCh
    L?CALL   _gcga
    endm
GLCDC?CCC  macro Xin ,Yin ,Cin
    MOVE?CB  Xin ,   _gx 
    MOVE?CB  Yin,    _gy 
    MOVE?CB  Cin,   _glcdCh
    L?CALL   _gcga 
    endm   
GLCDC?CCB  macro Xin ,Yin ,Bin
    MOVE?CB  Xin ,  _gx 
    MOVE?CB  Yin,    _gy 
    MOVE?BB  Bin, _glcdCh
    L?CALL   _gcga 
    endm  


    
   
GLetAddress macro Label, Wout
    BANKSEL Wout
    movlw low Label          ; get low byte
    movwf Wout
    movlw High Label         ; get high byte
    movwf Wout + 1  
    BANKSEL 0
    endm 
      
 IFDEF    TBLPTRL 
     
GLCD_Cstr_out
    tblrd   *+
    movf   TABLAT,w
    bz	GLCD_exit_Cstr_out  ; EXIT ON Null char 
    CHK?RP  _glcdCh 
    MOVWF   _glcdCh 
    CHK?RP  _glcd_bigaddress
    movff   TBLPTRU,_glcd_bigaddress
    movff   TBLPTRH,_glcd_bigaddress+1
    movff   TBLPTRL,_glcd_bigaddress+2
    L?CALL  _gcga
    CHK?RP  _glcd_bigaddress
    movff   _glcd_bigaddress   ,TBLPTRU
    movff   _glcd_bigaddress+1 ,TBLPTRH
    movff   _glcd_bigaddress+2 ,TBLPTRL
    bra     GLCD_Cstr_out        
GLCD_exit_Cstr_out
    BANKSEL 0
    return 
     


      
GLCD_str_out
    movf POSTINC1, W	; Get a character
    bz	GLCD_exit_strout  ; EXIT ON Null char 
    CHK?RP  _glcdCh 
    MOVWF _glcdCh
    BANKSEL 0
    L?CALL _gcga  
    bra    GLCD_str_out        
GLCD_exit_strout
    BANKSEL 0
    return    
 ELSE   


  
GLCD_str_out
    IFDEF BSR
        MOVIW FSR1++	; Get a character
        BTFSC STATUS,Z
        BRA	GLCD_exit_strout  ; EXIT ON Null char 
    ELSE
        movf INDF, W	; Get a character
       BTFSC STATUS,Z
        GOTO	GLCD_exit_strout  ; EXIT ON Null char 
        INCF FSR,F 
    ENDIF
    CHK?RP  _glcdCh 
    MOVWF _glcdCh
    MOVE?BB FSR1L,_glcd_bigaddress
    MOVE?BB FSR1H,_glcd_bigaddress+1
    BANKSEL 0
    L?CALL _gcga 
    MOVE?BB _glcd_bigaddress,FSR1L
    MOVE?BB _glcd_bigaddress+1,FSR1H
    GOTO  GLCD_str_out      
GLCD_exit_strout
    BANKSEL 0
    return     
 ENDIF 
endasm
    
    glcd_bigaddress  VAR BYTE[3]
    glcd_buff        VAR BYTE[32]
    BIG_TEXT    var byte 
    glcd_rad    var word
    glcdCh      var byte  'chr  DATA
    glcdData    VAR byte  'DATA
    glcdBC      VAR word  'gca  var
    glcdDC      VAR BYTE  'gca  var
    glcdFont    var word  bank0'font address
    glcdOffset  VAR word  'font offset
    glcdbm      VAR word  'bitmap offset
    gl          var byte  'width/height
    gy          var byte  'gca  pg   address
    gy_         var byte  'gca  pg   address
    gx          var byte  'gca  row  address
    gx_         var byte  'gca  row  address
    GRX         var byte  'DATA
    ctemp       var word
    ctemp1      var word
    ssd_add     var byte
    glcdStrAddr var word ext
@glcdStrAddr =   _glcd_bigaddress 


GlcdUnpackStr:     
    readcode glcdStrAddr,CTEMP
    glcd_bigaddress[2]  = CTEMP&$7f
    ctemp=ctemp<<1
    glcdCh = CTEMP.HIGHBYTE 
    glcdStrAddr=glcdStrAddr+1
    if   glcdCh then 
        gosub gcga
        glcdCh =  glcd_bigaddress[2]
    else
        return
    endif
    if   glcdCh then 
        gosub gcga
    else
        return
    endif
    goto   GlcdUnpackStr:     
return    
    
    
 
glcd_init: 
#ifdef hwi2c
    SSPSTAT = 0 'High Speed Filter
    SSPADD = $26'400 kHz @32 MHz
    SSPCON1 = %00101000 'I2C Master Mode Enable
    SSPCON3 = 0
    
#endif
    @ GLetAddress _font7x5,_glcdFont
    ssd_add = sdd1306_addr 
    SSDc $AE ' Display OFF
    SSDc $d5 
    SSDc $80 
    SSDc $a8 : SSDc $3f 
    SSDc $D3 : SSDc $00 ; Set Display Offset Mode Set 0  
    if ssdheight > 3  then
        SSDc $40   ' Set display start line 0 
    else
        SSDc $60   ' Set display start line 4 
    endif 
    SSDc $8D : SSDc $14 ' Set Charge Pump Internal
    SSDc $20 : SSDc $00 ' Adressing mode Horizontal
    SSDc $A1   ' set segment remap column 127 as start
    SSDc $C8   ' Com Scan Direction, Flip display vertically
    SSDc $DA   ' set COM pins
    if ssdheight > 3  then
        SSDc$12  ' set COM pins = 128x64=$12   
    else
        SSDc$02  ' set COM pins = 128x32=$02
    endif 
    SSDc $81 : SSDc$7F  ' Set brightness to $01 to $FF  ($7F is default, $01 is faint)
    SSDc $DB : SSDc$40  ' Set VCOM Deselect Level
    SSDc $B0  ' Set Page Address From $B0 to $B7 
    SSDc $2e  ; scroll off
    SSDc $A4  ' display ON continue
    SSDc $A6  ' $A6=NORMAL MODE;  $A7=INVERSE MODE
    SSDc $AF  ' Display ON
return 




xyx:  ;draw HORIZ LINE @X,Y for W len   0<X>127   1<W>127
    FOR GRX = 0 TO 31
        glcd_buff[GRX] = glcdData  ;uses this var to set which bit/s is used to generate line
    NEXT
    gx = gx&ssdwidth
    gx_= gx + gl
    gy = gy&ssdheight
    gy_= gy
    gosub   setxy
    GRX = gl/32
    glcd_rad = 32
    WHILE GRX
        gosub ssd_data
        GRX = GRX-1
    WEND
    glcd_rad = gl//32
    IF glcd_rad  THEN
        gosub ssd_data
    ENDIF
return 




xyy:       ;draw VERT LINE @X,Y for W len   @X 0<X>127   1<W>7  
    FOR GRX = 0 TO ssdheight
        glcd_buff[GRX] = 255
    NEXT
    gx = gx&ssdwidth
    gx_= gx
    gy = gy&ssdheight
    gy_= gy+GL
    gosub   setxy
    glcd_rad = gl
    gosub ssd_data
return
      
    
glcd_clrxy:    ' clear area  x1y1 to x2 y2
    FOR GRX = 0 TO 31
        glcd_buff[GRX] = 0
    NEXT
    CTEMP = (1 + GX_ - GX)*(1 + GY_ -  GY)
    gosub   setxy
    GRX = CTEMP/32
    glcd_rad=32
    WHILE GRX
        gosub ssd_data
        GRX = GRX-1
    WEND
    glcd_rad = CTEMP//32
    IF GRX THEN
        gosub ssd_data
    ENDIF
return
  
    
gcga:     ;draw a chr
    GY = gy&ssdheight      
    GY_= gy + BIG_TEXT 
    gx = gx&ssdwidth
    #ifdef PIC16
    glcdOffset = (glcdch-32)*3 + glcdFont  ; point to cga data
    #ELSE
    glcdOffset = (glcdch-32)*6 + glcdFont  ; point to cga data
    #ENDIF
    gosub unpack
    IF BIG_TEXT THEN 
        GOSUB SSD_BIG
        glcd_rad = 24
        gx_= gx + 11
    ELSE
        glcd_rad = 6
        gx_= gx + 5
    ENDIF
    gosub setxy
    gosub ssd_data
    gx = gx_+ 1 + BIG_TEXT 
    IF GX > 121  THEN  gx=0    ;wrap 
return   


ssd_data:   ;send data block
#ifdef hwi2c
 glcdBC=0
 SSPCON2.0 = 1 ; SEN - Start Condition Enable Bit 
 WHILE SSPCON2.0 = 1 : WEND ; Wait for Start to complete
 SSPBUF = ssd_add ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 SSPBUF = $40 ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 while  glcdBC < glcd_rad
     SSPBUF = glcd_buff[glcdBC] ; Move data to SSPBUF
     WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
     While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
     glcdBC=glcdBC+1   
 wend   
 SSPCON2.2 = 1 ; PEN - send stop bit
 While SSPCON2.2 = 1 : Wend ; Wait for SSP to complete
#else
 i2Cwrite SDA,SCL,ssd_add,[$40,str glcd_buff\ glcd_rad]
#endif 
return 
#ifndef PIC16   
ssd_bitmap:   ;send graphic block from flash
 gosub setxy
 glcdBC=0
 SSPCON2.0 = 1 ; SEN - Start Condition Enable Bit 
 WHILE SSPCON2.0 = 1 : WEND ; Wait for Start to complete
 SSPBUF = ssd_add ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 SSPBUF = $40 ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 while  glcdBC < glcd_rad
     readcode glcdbm+glcdBC,CTEMP
     SSPBUF = ctemp.LOWBYTE ; Move data to SSPBUF
     WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
     While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave
     SSPBUF = ctemp.highBYTE ; Move data to SSPBUF
     WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
     While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
     glcdBC=glcdBC+2  
 wend   
 SSPCON2.2 = 1 ; PEN - send stop bit
 While SSPCON2.2 = 1 : Wend ; Wait for SSP to complete
return  
#endif        
       
SSD_BIG:     ;create a big chr from a small one
   for glcddc = 5 to 0 STEP -1
   ctemp = 0
   ctemp1 = 3
   gL = glcd_buff[glcddc]
   for glcdBc = 0 to 7
       IF  GL & 1 THEN ctemp = ctemp|ctemp1
       ctemp1 = ctemp1<<2
       GL = GL>>1
   NEXT
   gL = glcddc*2
   glcd_buff[GL]   =ctemp.LOWBYTE
   glcd_buff[GL+1] =ctemp.LOWBYTE
   glcd_buff[GL+12]=ctemp.HIGHBYTE
   glcd_buff[GL+13]=ctemp.HIGHBYTE
   NEXT
RETURN


unpack:      ;unpack font from flash
   for glcddc = 0 to 2
       GL = glcddc<<1
       readcode glcdOffset,CTEMP
#ifdef PIC16
       glcd_buff[gl]  = CTEMP&$7f
       ctemp=ctemp<<1
       glcd_buff[gl+1]= CTEMP.HIGHBYTE
       glcdOffset     = glcdOffset + 1 
#else 
       glcd_buff[gl]  = CTEMP
       glcd_buff[gl+1]= CTEMP.HIGHBYTE 
       glcdOffset     = glcdOffset + 2 
#endif 
   next
return
      
    
cmd_byte:  'send command sequence "glcdData "
#ifdef hwi2c
 ;hw i2c
 SSPCON2.0 = 1 ; SEN - Start Condition Enable Bit 
 WHILE SSPCON2.0 = 1 : WEND ; Wait for Start to complete
 SSPBUF = ssd_add ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 SSPBUF = 0 ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 SSPBUF = glcdData ; Move data to SSPBUF
 WHILE SSPSTAT.2 = 1 : WEND ; SSPSTAT = 1 Transmit in progress
 While SSPCON2.6 = 1 : WEND ; Wait for Acknowledge from slave 
 SSPCON2.2 = 1 ; PEN - send stop bit
 While SSPCON2.2 = 1: Wend ; Wait for SSP to complete
#else 
 ;soft i2c
   I2Cwrite SDA,SCL,ssd_add,[0,glcdData]
#ENDIF
return 




setxy:    ;set PAGE  WINDOW      
    SSDc $22
    SSDc gy
    SSDc gy_
    SSDc $21
    SSDc gx
    SSDc gx_       
return         






overglcd :

**flotulopex** · - 16th November 2023, 05:51

Thanks a lot guys 👍

I'll give it a try this week-end.

And thanks Richard for condensing the information here

**flotulopex** · - 17th November 2023, 22:03

Only garbage at this time...but it's alive

Name: 72x40_first_life.png
Views: 559
Size: 501.7 KB

**Ioannis** · - 18th November 2023, 13:24

Seems that the character size is too big to fit there..

Ioannis

**flotulopex** · - 19th November 2023, 08:04

...still struggeling with the ssd1306's datasheet to understand the "page" concept and how to display things.

This is the simplest and shortest code I'm working with for now, composed of different sources I found in this forum and also on ARDUINO's one:

Code:

' ====== DESCRIPTION ===============================================================================
' Use mini OLED 72x40 pixel display

' ====== FUSES =====================================================================================
' PIC 16F690 Fuses
' Internal oscillator  (activate OSCCON register)
@ __config _FCMEN_OFF &_IESO_OFF &_CPD_OFF &_WDT_OFF &_INTRC_OSC_NOCLKOUT &_BOR_OFF &_CP_OFF &_PWRTE_OFF &_MCLRE_OFF

@ ERRORLEVEL -306
@ ERRORLEVEL -202

' ====== REGISTERS =================================================================================
'             76543210
OPTION_REG = %10000000 'PORT A&B Pull-Ups disabled (see WPUA & WPUB)
OSCCON     = %01100000 'Internal RC set to 4MHZ
'ANSEL      = %00000000 'Select analog inputs Channels 0 to 7 (AN2 + AN4 selected)
'ANSELH     = %00000000 'Select analog inputs Channels 8 to 11
'ADCON0     = %10000000 'A/D Module (Bit5:2 select channels 0:11)
'ADCON1     = %00000000 'A/D control register
'CM1CON0    = %00000000 'Comparator1 Module is OFF
'CM2CON0    = %00000000 'Comparator2 Module is OFF
'INTCON     = %00000000 'INTerrupts CONtrol (TMR0 OFF)
'TRISA      = %00000000 'Set Input/Output (0 to 5)
'PORTA      = %00000000 'Ports High/Low (0 to 5)
'TRISB      = %00000000 'Set Input/Output (4 to 7)
'PORTB      = %00000000 'Ports High/Low (4 to 7)
'TRISC      = %00000000 'Set Input/Output (0 to 7)
'PORTC      = %00000000 'Ports High/Low (0 to 7)

' ====== DEFINES ===================================================================================
DEFINE OSC 4
'DEFINE NO_CLRWDT 1   'Don't waste cycles clearing WDT  
'DEFINE HSER_CLOERR 1 'Automatic clear overrun error 

' ====== VARIABLES =================================================================================
I2CDevice   var byte

SDA         VAR PORTB.4 ' I2C Data
SCL         VAR PORTB.6 ' I2C Clock

TEXT        VAR BYTE[20]
LENGTH      VAR BYTE[2]
DC          VAR Byte    ' "DATA OR COMMAND", $40=DATA; $0=COMMAND --> changed from bit to byte
LCD_DATA    VAR BYTE   
COM         VAR BYTE    ' COMMAND

I           VAR BYTE
J           VAR BYTE
X           VAR BYTE  'LCD POSITION X(0 TO 127)
Y           VAR BYTE  'LCD POSITION Y(0 TO 7)

' ====== INITIALIZE VARIABLES ======================================================================
I2CDevice = $78

'======= SSD1306 I2C OLED initialization ===========================================================
COM = $AE : GOSUB SEND_COMMAND ' turn off oled panel
COM = $D5 : GOSUB SEND_COMMAND ' set display clock divide ratio/oscillator frequency
COM = $80 : GOSUB SEND_COMMAND ' set divide ratio
COM = $A8 : GOSUB SEND_COMMAND ' set multiplex ratio
COM = $27 : GOSUB SEND_COMMAND ' 1/40 duty
COM = $D3 : GOSUB SEND_COMMAND ' set display offset
COM = $00 : GOSUB SEND_COMMAND ' not offset
COM = $AD : GOSUB SEND_COMMAND ' Internal IREF Setting	
COM = $30 : GOSUB SEND_COMMAND ' --
COM = $8D : GOSUB SEND_COMMAND ' set Charge Pump enable/disable
COM = $14 : GOSUB SEND_COMMAND ' set(0x10) disable
COM = $40 : GOSUB SEND_COMMAND ' set start line address
COM = $A6 : GOSUB SEND_COMMAND ' set normal display
COM = $A4 : GOSUB SEND_COMMAND ' Disable Entire Display On
COM = $A1 : GOSUB SEND_COMMAND ' set segment re-map 128 to 0
COM = $C8 : GOSUB SEND_COMMAND ' Set COM Output Scan Direction 64 to 0
COM = $DA : GOSUB SEND_COMMAND ' set com pins hardware configuration
COM = $12 : GOSUB SEND_COMMAND '
COM = $81 : GOSUB SEND_COMMAND ' set contrast control register
COM = $AF : GOSUB SEND_COMMAND ' 
COM = $D9 : GOSUB SEND_COMMAND ' set pre-charge period
COM = $22 : GOSUB SEND_COMMAND '
COM = $DB : GOSUB SEND_COMMAND ' set vcomh
COM = $20 : GOSUB SEND_COMMAND ' 
COM = $AF : GOSUB SEND_COMMAND ' turn on oled panel    

' ====== PROGRAM ===================================================================================
PAUSE 20
GOSUB CLEAR_LCD
GOSUB TITLE

MAIN:
    PAUSE 1000
    GOTO MAIN
END

' ====== CLEAR LCD =================================================================================
CLEAR_LCD:
    FOR J = 0 TO 7 
        FOR I = 0 TO 71 '127
            LCD_DATA = $00 : GOSUB SEND_DATA
        NEXT I
    NEXT J                             
    RETURN 
    
' ====== SEND COMMAND ==============================================================================
SEND_COMMAND:
    dc = $0
    I2CWrite SDA,SCL,I2CDevice,DC,[COM]
    dc = $40
    RETURN 
    
' ====== CLEAR LCD =================================================================================
SEND_DATA:
    DC = $40
    I2CWrite SDA,SCL,I2CDevice,DC,[LCD_DATA]
    RETURN
    
' ====== SEND DATA =================================================================================
FILL:
    FOR J = 0 TO 7
        FOR I = 0 TO 71 '127
            LCD_DATA = $FF : GOSUB SEND_DATA
        NEXT I
    NEXT J
    RETURN
    
' ====== TITLE =====================================================================================
TITLE:
    X = 0 : Y = 0 : GOSUB SET_XY
    FOR I = 0 TO 71 '127
        LOOKUP I,[$00,$40,$60,$50,$7E,$50,$60,$40,$02,$06,$0E,$1E,$3E,$00,$00,$00,_
        $00,$00,$00,$00,$00,$1F,$3F,$60,$60,$60,$60,$60,$60,$3C,$1C,$00,_
        $00,$7F,$7F,$61,$61,$61,$61,$61,$61,$3F,$1E,$00,$00,$1E,$3F,$61,_
        $61,$61,$61,$61,$61,$38,$18,$00,$00,$00,$00,$00,$00,$00,$00,$00,_
        $00,$00,$00,$00,$00,$00,$00,$1F,$3F,$60,$60,$60,$60,$60,$60,$3C,_
        $1C,$00,$00,$1E,$3F,$61,$61,$61,$61,$61,$61,$38,$18,$00,$00,$3F,_
        $7F,$60,$18,$06,$06,$18,$60,$7F,$3F,$00,$00,$00,$00,$00,$00,$00,_
        $00,$00,$00,$1C,$63,$41,$5D,$41,$5D,$41,$5D,$41,$5D,$41,$7F,$00],LCD_DATA
        lcd_data = lcd_data rev 8
        GOSUB SEND_DATA
    NEXT I

    X = 0 : Y = 1 : GOSUB SET_XY
    for i = 0 to 71 '127
        lookup i,[$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,_
        $00,$00,$00,$00,$00,$F8,$FC,$06,$06,$06,$C6,$C6,$C6,$FC,$F8,$00,_
        $00,$FE,$FE,$80,$80,$80,$80,$80,$80,$00,$00,$00,$00,$18,$1C,$86,_
        $86,$86,$86,$86,$86,$FC,$78,$00,$00,$00,$00,$00,$00,$00,$00,$00,_
        $00,$00,$00,$00,$00,$00,$00,$F8,$FC,$06,$06,$06,$C6,$C6,$C6,$FC,_
        $F8,$00,$00,$18,$1C,$86,$86,$86,$86,$86,$86,$FC,$78,$00,$00,$FE,_
        $FE,$00,$00,$00,$00,$00,$00,$FE,$FE,$00,$00,$00,$00,$00,$00,$00,_
        $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00],lcd_data
        lcd_data=lcd_data rev 8
        GOSUB SEND_DATA
    NEXT I

    X = 0 : Y = 3 : GOSUB SET_XY
    for i = 0 to 71 '127
        lookup i,[$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$3C,$7E,$C3,$C3,$C3,$C3,_
        $C3,$C3,$71,$30,$00,$00,$7F,$FF,$C3,$C3,$C3,$C3,$C3,$C3,$C3,$C3,_
        $00,$00,$7F,$FF,$C1,$C1,$C1,$C1,$C1,$C1,$FF,$7F,$00,$00,$7F,$FF,_
        $C3,$C3,$C3,$C3,$C3,$C3,$7E,$3C,$00,$00,$3F,$7F,$C0,$C0,$C0,$C0,_
        $C0,$C0,$70,$30,$00,$00,$FF,$FF,$03,$03,$03,$03,$03,$03,$FF,$FF,_
        $00,$00,$C0,$C0,$C0,$C0,$FF,$FF,$C0,$C0,$C0,$C0,$00,$00,$FF,$FF,_
        $0C,$0C,$03,$03,$00,$00,$FF,$FF,$00,$00,$3F,$7F,$C0,$C0,$C0,$C1,_
        $C1,$C1,$79,$39,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00],lcd_data
        lcd_data=lcd_data rev 8
        GOSUB SEND_DATA
    NEXT I

    X = 0 : Y = 4 : GOSUB SET_XY
    for i = 0 to 71 '127
        lookup i,[$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$30,$38,$0C,$0C,$0C,$0C,_
        $0C,$0C,$F8,$F0,$00,$00,$F8,$FC,$0C,$0C,$0C,$0C,$0C,$0C,$0C,$0C,_
        $00,$00,$FC,$FC,$80,$80,$80,$80,$80,$80,$FC,$FC,$00,$00,$FC,$FC,_
        $80,$C0,$60,$30,$18,$0C,$04,$00,$00,$00,$F0,$F8,$0C,$0C,$0C,$0C,_
        $0C,$0C,$38,$30,$00,$00,$FC,$FC,$00,$00,$00,$00,$00,$00,$FC,$FC,_
        $00,$00,$0C,$0C,$0C,$0C,$FC,$FC,$0C,$0C,$0C,$0C,$00,$00,$FC,$FC,_
        $00,$00,$00,$00,$C0,$C0,$FC,$FC,$00,$00,$F0,$F8,$0C,$0C,$0C,$8C,_
        $8C,$8C,$F8,$F0,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00],lcd_data
        lcd_data=lcd_data rev 8
        GOSUB SEND_DATA
    NEXT I

    X = 0 : Y = 5 : GOSUB SET_XY
    for i = 0 to 71 '127
        lookup i,[$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$1F,$3F,$30,$30,$30,$30,_
        $30,$30,$30,$30,$00,$00,$0F,$1F,$30,$30,$30,$30,$30,$30,$1F,$0F,_
        $00,$00,$1F,$3F,$30,$30,$30,$30,$30,$30,$1F,$0F,$00,$00,$00,$00,_
        $00,$00,$00,$0F,$1F,$30,$30,$30,$30,$30,$30,$1C,$0C,$00,$00,$30,_
        $30,$30,$30,$3F,$3F,$30,$30,$30,$30,$00,$00,$0F,$1F,$30,$30,$30,_
        $30,$30,$30,$1E,$0E,$00,$00,$3F,$3F,$03,$03,$00,$00,$00,$00,$3F,_
        $3F,$00,$00,$1F,$3F,$30,$30,$30,$30,$30,$30,$3F,$1F,$00,$00,$3F,_
        $3F,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00],lcd_data
        lcd_data=lcd_data rev 8
        GOSUB SEND_DATA
    NEXT I

    X = 0 : Y = 6 : GOSUB SET_XY
    for i = 0 to 71 '127
        lookup i,[$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$FF,$FF,$C0,$C0,$C0,$C0,_
        $C0,$C0,$00,$00,$00,$00,$FC,$FE,$03,$03,$03,$03,$03,$03,$FE,$FC,_
        $00,$00,$FF,$FF,$E0,$F0,$D8,$CC,$C6,$C3,$81,$00,$00,$00,$00,$00,_
        $00,$00,$00,$0C,$8E,$C3,$C3,$C3,$C3,$C3,$C3,$7E,$3C,$00,$00,$03,_
        $03,$03,$03,$FF,$FF,$03,$03,$03,$03,$00,$00,$FC,$FE,$03,$03,$03,_
        $63,$63,$63,$7E,$7C,$00,$00,$FF,$FF,$00,$00,$C0,$C0,$30,$30,$FF,_
        $FF,$00,$00,$FF,$FF,$60,$60,$60,$60,$60,$60,$FF,$FF,$00,$00,$FF,_
        $FF,$03,$03,$03,$03,$03,$03,$03,$03,$00,$00,$00,$00,$00,$00,$00],lcd_data
        lcd_data=lcd_data rev 8
        GOSUB SEND_DATA
    NEXT I
    RETURN
    
'======= SET_XY ====================================================================================
SET_XY:
    COM = $21 : GOSUB SEND_COMMAND
    COM = X   : GOSUB SEND_COMMAND
    COM = 71  : GOSUB SEND_COMMAND
    COM = $22 : GOSUB SEND_COMMAND
    COM = Y   : GOSUB SEND_COMMAND
    COM = 41  : GOSUB SEND_COMMAND
    RETURN

Seems that the character size is too big to fit there..

Originally, this code is made for a larger display so I need to adapt it.

**Ioannis** · - 19th November 2023, 12:46

Is it worth it the effort to spend much time on this LCD's?

It tried it and seems a lot of waste of time. Also too small for my age

Ioannis

**flotulopex** · - 12th December 2023, 16:52

Originally Posted by Ioannis

These LCD's are difficult to use. Indeed there are too many parameters to set....

Yes, I agree, this is definitively the hardest part to get it work.

Richard, how did you come to this $68 value please? I can't figure it out

Name: 2023-12-12 17_44_38-SSD1306 COMMAND reference.pdf - [SSD1780] - SumatraPDF.png
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'======= SSD1306 I2C OLED initialization ================================================== =========
COM = $AE : GOSUB SEND_COMMAND ' turn off OLED panel
COM = $D5 : GOSUB SEND_COMMAND ' set display clock divide ratio/oscillator frequency
COM = $F0 : GOSUB SEND_COMMAND ' set divide ratio
COM = $A8 : GOSUB SEND_COMMAND ' set multiplex ratio
COM = $27 : GOSUB SEND_COMMAND ' 1/40 duty
COM = $D3 : GOSUB SEND_COMMAND ' set display offset
COM = $00 : GOSUB SEND_COMMAND
COM = $40 : GOSUB SEND_COMMAND ' set display start line
COM = $8D : GOSUB SEND_COMMAND ' set Charge Pump enable/disable
COM = $14 : GOSUB SEND_COMMAND ' set(0x10) disable
COM = $20 : GOSUB SEND_COMMAND ' Addressing Setting Command Table
COM = $00 : GOSUB SEND_COMMAND ' Page Addressing Mode
COM = $A1 : GOSUB SEND_COMMAND ' set segment re-map: column address 127 is mapped to SEG0
COM = $C8 : GOSUB SEND_COMMAND ' Set COM Output Scan Direction 64 to 0
COM = $DA : GOSUB SEND_COMMAND ' set com pins hardware configuration
COM = $12 : GOSUB SEND_COMMAND ' Sequential COM pin configuration
COM = $AD : GOSUB SEND_COMMAND ' Internal IREF Setting
COM = $30 : GOSUB SEND_COMMAND ' --
COM = $81 : GOSUB SEND_COMMAND ' set contrast control register
COM = $2F : GOSUB SEND_COMMAND ' set contrast value 0..255
COM = $D9 : GOSUB SEND_COMMAND ' set pre-charge period
COM = $22 : GOSUB SEND_COMMAND ' set pre-charge value
COM = $DB : GOSUB SEND_COMMAND ' set vcomh deselect level
COM = $20 : GOSUB SEND_COMMAND ' set vcomh value
COM = $A4 : GOSUB SEND_COMMAND ' Disable Entire Display On
COM = $A6 : GOSUB SEND_COMMAND ' set normal display
COM = $0C : GOSUB SEND_COMMAND ' set lower column address
COM = $11 : GOSUB SEND_COMMAND ' set higher column address
COM = $68 : GOSUB SEND_COMMAND ' set display start line register
COM = $AF : GOSUB SEND_COMMAND ' turn on OLED panel

**richard** · - 12th December 2023, 21:09

Richard, how did you come to this $68 value please? I can't figure it out

the info supplied with the display makes calculating the value somewhat difficult . in fact i cannot see the connection at all

the command basically sets where the memory line representing page 0 bit 0 maps to the physical display top row pixels, it can be vertically offset by 0 to 63 pixels in a virtually identical way to the way the display scrolls horizontally

it needed to be offset by -23 pixels to get the top row to align with page 0 bit 0

command range = 0x40 to 0x7f , 0x7f - 23 = 0x68

**flotulopex** · - 14th December 2023, 12:46

Well, I think I'm just gonna remember this settings "as is".

Thanks for trying to make things more clear for me

**CuriousOne** · - 15th December 2023, 05:19

This is very interesting thread, giving me some hope that I will be able to use OLED screens with PBP one day, but I have a quesiton - 24C64 or something like that costs under $1. Why not use it for font storage?

**richard** · - 16th December 2023, 04:40

I have a quesiton - 24C64 or something like that costs under $1. Why not use it for font storage

because you can save your $1 and another one by buying a better pic to start with and :-

not have a costlier more complex circuit board .
use a standard font file generated by glcd font creator.
its faster, uses hardware i2c and can do proper graphics too.

as i said at the beginning if you want easy get a pic 18

Name: prices.jpg
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Name: prices.jpg
Views: 228
Size: 173.6 KB

**CuriousOne** · - 16th December 2023, 06:39

So expensive

I'm buying 2nd hand 886 and 1829 for about 50 and 90 cents in China

Since I'm not doing anything commercial, this is just fine for me.

**CuriousOne** · - 16th December 2023, 06:40

And by the way, I don't see any reasons, why you can't write GLCD (which can't save file on windows 10-11) generated or any other software generated font into external EEPROM.

Thread: SSD1306 OLED (72x40) I2C display from scratch

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Re: SSD1306 OLED (42x40) I2C display from scratch