Originally Posted by
iw2fvo
Steve, very good result !
I think It will help a lot of people too .
I am wait to receive the item ( about 20 days ).
Could you please post the code : I will start to study it .
Thanks
Ambrogio
Here it is. This is a simple test program for PBP2.5 or lower. Anything you do not understand please ask. The next step is to include the command selection inside the LCD_WRITE subroutine.
Code:
'****************************************************************
'* 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_BuffSize CON 30
'LCD_Buff VAR BYTE[LCD_BuffSize]
'LCD_BuffAddr CON EXT : @LCD_BuffAddr = _LCD_Buff
'LCD_BuffLen VAR WORD ; 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_Data = $28 : gosub LCD_Write ; Function Set, 4-bit, 2-line, 5x7
LCD_Data = $0C : gosub LCD_Write ; Display ON
LCD_Data = $01 : gosub LCD_Write ; Clear Screen
PAUSE 50
LCD_Data = $06 : gosub LCD_Write ; Entry Mode
PAUSE 2 ; Let command finish
LCD_RS = 1 ;Switch to Data
;Print Static Background to LCD
LCD_Data = " " : gosub LCD_Write ;Line 1
LCD_Data = " " : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = "S" : gosub LCD_Write
LCD_Data = "t" : gosub LCD_Write
LCD_Data = "e" : gosub LCD_Write
LCD_Data = "v" : gosub LCD_Write
LCD_Data = "e" : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = "E" : gosub LCD_Write
LCD_Data = "a" : gosub LCD_Write
LCD_Data = "r" : gosub LCD_Write
LCD_Data = "l" : gosub LCD_Write
lcd_rs = 0 ;Command is next
lcd_data=$a8 : gosub lcd_write ;Move to start of line 2
pause 2
lcd_rs = 1 ;Switch back to Data
LCD_Data = " " : gosub LCD_Write ;Line 2
LCD_Data = " " : gosub LCD_Write
LCD_Data = "D" : gosub LCD_Write
LCD_Data = "a" : gosub LCD_Write
LCD_Data = "t" : gosub LCD_Write
LCD_Data = "a" : gosub LCD_Write
LCD_Data = "g" : gosub LCD_Write
LCD_Data = "e" : gosub LCD_Write
LCD_Data = "o" : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = "L" : gosub LCD_Write
LCD_Data = "i" : gosub LCD_Write
LCD_Data = "m" : gosub LCD_Write
LCD_Data = "i" : gosub LCD_Write
LCD_Data = "t" : gosub LCD_Write
LCD_Data = "e" : gosub LCD_Write
LCD_Data = "d" : gosub LCD_Write
lcd_rs = 0 ;Command is next
lcd_data=$99 : gosub lcd_write ;Move to line 3 col 6
pause 2
lcd_rs = 1 ;Switch back to Data
LCD_Data = "*" : gosub LCD_Write ;Line 3
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
LCD_Data = "*" : gosub LCD_Write
lcd_rs = 0 ;Command is next
lcd_data=$D8 : gosub lcd_write ;Move to line 4 col 5
pause 2
lcd_rs = 1 ;Switch back to Data
LCD_Data = "T" : gosub LCD_Write ;Line 4
LCD_Data = "e" : gosub LCD_Write
LCD_Data = "s" : gosub LCD_Write
LCD_Data = "t" : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = "P" : gosub LCD_Write
LCD_Data = "r" : gosub LCD_Write
LCD_Data = "o" : gosub LCD_Write
LCD_Data = "g" : gosub LCD_Write
LCD_Data = "r" : gosub LCD_Write
LCD_Data = "a" : gosub LCD_Write
LCD_Data = "m" : gosub LCD_Write
pause 5000
lcd_rs = 0 ;Command is next
lcd_data=$D8 : gosub lcd_write ;Move to line 4 col 5
pause 2
lcd_rs = 1 ;Switch back to Data
LCD_Data = " " : gosub LCD_Write ;Clear line 4 and set clock
LCD_Data = " " : gosub LCD_Write
LCD_Data = "0" : gosub LCD_Write
LCD_Data = "0" : gosub LCD_Write
LCD_Data = ":" : gosub LCD_Write
LCD_Data = "0" : gosub LCD_Write
LCD_Data = "0" : gosub LCD_Write
LCD_Data = ":" : gosub LCD_Write
LCD_Data = "0" : gosub LCD_Write
LCD_Data = "0" : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
LCD_Data = " " : gosub LCD_Write
main: ;Count seconds and refresh the clock
for hours = 0 to 23
for minutes = 0 to 59
for seconds = 0 to 59
lcd_rs = 0 ;Command is next
lcd_data=$DA : gosub lcd_write ;Move to line 4 col 7
pause 2
lcd_rs = 1 ;Switch back to Data
LCD_Data = (hours dig 1)+48 : gosub LCD_Write
LCD_Data = (hours dig 0)+48 : gosub LCD_Write
LCD_Data = ":" : gosub LCD_Write
LCD_Data = (minutes dig 1)+48 : gosub LCD_Write
LCD_Data = (minutes dig 0)+48 : gosub LCD_Write
LCD_Data = ":" : gosub LCD_Write
LCD_Data = (seconds dig 1)+48 : gosub LCD_Write
LCD_Data = (seconds dig 0)+48 : gosub LCD_Write
pause 1000
next ;second
next ;minute
next ;hour
goto main
LCD_WRITE:
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
return
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