I2C lcd ( arduino ) with PICBASIC, help

[EarlyBird2]

Ambrogio,

Any feedback?

If you have no questions then I will post the next improvement which includes the command in the LCD_Write subroutine. I am now looking at using arrays as the next step.

[EarlyBird2]

Ambrogio,

Any feedback?

If you have no questions then I will post the next improvement which includes the command in the LCD_Write subroutine. I am now looking at using arrays as the next step.

Here it is! including LOOKUP and ARRAYs.

'****************************************************************
'*  Name    : I2CLCD.BAS                                        *
'*  Author  : Steve Earl                                        *
'*  Notice  : Copyright (c) 2014 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 17/07/2014                                        *
'*  Version : 1.0                                               *
'*  Notes   : Serial I2C LCD using PBP 2.5                      *
'*          : PCF8574T I2C port expander 20x4 LCD               *
'****************************************************************

define OSC 40     ' set the correct speed here!!
'DEFINE I2C_SLOW 1
SDA         VAR PORTD.2       ; I2C Data pin
SCL         VAR PORTD.3       ; I2C Clock Pin
LCD_Addr CON 78               ; PCF8574T address
LCD_Line_1 con $80
LCD_Line_2 con $A8
LCD_Line_3 con $94
LCD_Line_4 con $D4
LCD_BuffSize    CON 22

LCD_Buff        VAR BYTE[LCD_BuffSize]
'LCD_BuffAddr    CON EXT : @LCD_BuffAddr = _LCD_Buff
LCD_BuffLen     VAR byte        ; Length of data in buffer
LCD_Data        VAR BYTE        ; Data to Send to LCD
LCD_Byte        VAR BYTE        ; Nibbles to Send
LCD_RS          VAR LCD_Byte.0  ; Register Select bit
LCD_RW          VAR LCD_Byte.1  ; Read/Write bit
LCD_E           VAR LCD_Byte.2  ; Enable bit
LCD_BackLight   VAR LCD_Byte.3  ; Backlight 1=ON
LCD_WriteMode   VAR BYTE        ; 1=LowNibble, 2=HighNibble, 3=Both
LCD_CommandMode VAR BIT         ; Indicates next byte is a command
LCD_Byte2       VAR BYTE        ; Same nibble without E bit
LCD_Idx         VAR BYTE


seconds var byte
minutes var byte
hours   var byte

Init:
;----[Initialize the LCD]-------------------------------------------------------
PAUSE 250                           ; LCD Power-on delay
LCD_Backlight = 1                   ; Backlight On
LCD_RW = 0                          ; Write to LCD
LCD_RS = 0                          ; Command Register
LCD_WriteMode = 1                   ;-- Low Nibbles only
LCD_Data = 3                        ; Software Reset 3 times
gosub LCD_Write : PAUSEUS 6000
gosub LCD_Write : PAUSEUS 1000
gosub LCD_Write : PAUSEUS 1000
LCD_Data = 2                        ; Start 4-bit mode
gosub LCD_Write : PAUSEUS 1000
LCD_WriteMode = 3                   ;-- Both Nibbles
LCD_buff[0] = $28                   ; Function Set, 4-bit, 2-line
LCD_buff[1] = $0C                   ; Display ON
LCD_buff[2] = $FE 
LCD_buff[3] = $06                   ; Entry Mode
LCD_buff[4] = $FE 
LCD_buff[5] = $01                   ; Clear Screen
lcd_bufflen = 6
gosub LCD_Buff_Write

;Print Static Background to LCD
for lcd_idx = 0 to 85
               ;|                    | 20 characters
lookup lcd_idx,["     Steve Earl     ",_            ;20
 $FE,lcd_line_2,"   Datageo Limited  ",_            ;+22 = 42
 $FE,lcd_line_3,"     **********     ",_            ;+22 = 64
 $FE,lcd_line_4,"      00:00:00      "],lcd_data    ;+22 = 86  (0-85)
 gosub lcd_write
next

;Set up fixed buffer characters
lcd_bufflen = 10                     ;8 characters in clock + $FE + LCD_Line
LCD_buff[0] = $FE                   ;Command is next
LCD_buff[1] = lcd_line_4 + 6        ;Move to line 4 col 7
LCD_buff[4] = ":"                   ;Fixed characters
LCD_buff[7] = ":"                   ;       "
main:                               ;Count seconds and refresh the clock
for hours = 0 to 23
    for minutes = 0 to 59
        for seconds = 0 to 59  
            LCD_buff[2] = (hours dig 1)+48  
            LCD_buff[3] = (hours dig 0)+48 
            LCD_buff[5] = (minutes dig 1)+48 
            LCD_buff[6] = (minutes dig 0)+48 
            LCD_buff[8] = (seconds dig 1)+48 
            LCD_buff[9]= (seconds dig 0)+48 
            gosub lcd_buff_write
            pause 1000
        next    ;second
    next    ;minute
next    ;hour
goto main

LCD_WRITE:
if lcd_data = $FE then
    lcd_commandMode = 1                 ;Next byte Command
    lcd_rs = 0                          ;Switch to Command Register
else                                              
    LCD_E = 1                     
    IF LCD_WriteMode.1 = 1 THEN          ; Write High Nibble
     LCD_Byte = (LCD_Byte & $0F) | (LCD_Data  & $F0)
     LCD_Byte2 = LCD_Byte & $FB    
     I2CWRITE SDA,SCL, LCD_Addr,[LCD_Byte, LCD_Byte2]
    ENDIF
    
    IF LCD_WriteMode.0 = 1 THEN     ; Write Low Nibble
     LCD_Byte = (LCD_Byte & $0F) | ((LCD_Data << 4 )& $F0)
     LCD_Byte2 = LCD_Byte & $FB
     I2CWRITE SDA,SCL, LCD_Addr,[LCD_Byte, LCD_Byte2]
    ENDIF
    if lcd_commandmode then
     lcd_commandmode = 0              ;Reset to data
     lcd_rs = 1                       ;Switch to Data Register
     pause 2
    endif
endif
return

Lcd_Buff_Write:
 for lcd_idx = 0 to lcd_bufflen - 1
  lcd_data=lcd_buff[LCD_idx]
  gosub LCD_Write
 next
return

[iw2fvo]

Steve,
I am sorry for the delayed reply : I am not at home on those days.
I had a look to your code : it is a good work and I am waiting to check it soon when the hardware is arrived .
Thanks a lot for the assistance.
I think your work will help a lot of people .
Regards,
Ambrogio

[EarlyBird2]

Steve,
I am sorry for the delayed reply : I am not at home on those days.
I had a look to your code : it is a good work and I am waiting to check it soon when the hardware is arrived .
Thanks a lot for the assistance.
I think your work will help a lot of people .
Regards,
Ambrogio

You are welcome. More is on the way as I am now investigating embedded strings.

[EarlyBird2]

I tried using the on board EEPROM by using DATA and READ.

DATA "This is a string",0

but it stores only alternate characters. I was surprised it worked at all but the alternate characters? There has to be a reason for it to work this way.

[EarlyBird2]

I tried using the on board EEPROM by using DATA and READ.

DATA "This is a string",0

but it stores only alternate characters. I was surprised it worked at all but the alternate characters? There has to be a reason for it to work this way.

It looks like this was fixed back in 2010.

http://www.picbasic.co.uk/forum/showthread.php?t=12775

My PBP2.46 is from 2005.

[EarlyBird2]

It looks like this was fixed back in 2010.

http://www.picbasic.co.uk/forum/showthread.php?t=12775

My PBP2.46 is from 2005.

The plot thickens! Here is an extract from this thread http://www.picbasic.co.uk/forum/show...7143#post97143 using DATA with strings and it works.

EUREKA!
Thanks guys! You have been a huge help. I have finally figured it out.
My problem was more like 3 problems...

1. I have never done EEPROM stuff before so I was lost to begin with.
2. As Bruce pointed out, the mathematical order of operations in one line was not correct. I guess the BS2 thinks a little differently from PBP in that respect.
3. My PicBasic Pro compiler was Version 2.30 form 2000. It seems that v2.30 supports the PIC 16F628 but the PIC 16F628A was implemented in a later version. I have upgraded my PBP to version 2.47 and now the EEPROM features work correctly on the 16F628A. When I successfully tested a 16F84A using the same code, that lead me to question the compiler.

So for future generations and the benefit of other people like me, here's my WORKING code that is tested successfully on a PIC 16F628A with a 20MHz resonator compiled using PBP v2.47. It reads data from the Parallax RFID Reader Module, compares it against known values stored in EEPROM and allows or denies access accordingly. Enjoy.

CMCON = 7   
DEFINE OSC 20	'Set oscillator in MHz

' -----[ Variables ]-------------------------------------------------------

buf	VAR	Byte(10)	' RFID bytes buffer
tagNum	VAR	Byte	' from EEPROM table
idx	VAR	Byte	' tag byte index
char	VAR	Byte	' character from table

' -----[ EEPROM Data ]-----------------------------------------------------

Tag1	DATA	"100050A4B7"
Tag2	DATA	"1000508E0A"
Tag3	DATA	"10005091DC"
Tag4	DATA	"100050203A"
Tag5	DATA	"100050DA36"

' -----[ Initialization ]--------------------------------------------------

HIGH portb.3	' turn off RFID reader
LOW portb.6	' lock the door!
Low portb.4	'Turn off LED

' -----[ Program Code ]----------------------------------------------------

Main:

LOW portb.3				' activate the reader
SERIN2 portb.2, 396, [WAIT($0A), STR buf\10]	' wait for hdr + ID
HIGH portb.3				' deactivate reader

Check_List:
  FOR tagNum = 1 to 5			' scan through known tags
    FOR idx = 0 TO 9				' scan bytes in tag
    READ (((tagNum-1) * 10) + idx), char		' get tag data from table
    IF (char <> buf(idx)) THEN Bad_Char		' compare tag to table
    NEXT
    GOTO Tag_Found				' all bytes match!
Bad_Char:					' try next tag
  NEXT

Bad_Tag:
  tagNum = 0
  FREQOUT portb.5, 1000 */ $100, 115 */ $100	' groan
  PAUSE 1000
  GOTO Main

Tag_Found:
  HIGH portb.6				' remove latch
  High portb.4				' Light LED
  FREQOUT portb.5, 2000 */ $100, 880 */$100	' beep
  LOW portb.6				' restore latch
  Low portb.4				' LED OFF
  GOTO Main