Ok enough of my whining, here is some workable code, thanks to Darrel Taylor, well mostly about 99 percent. He wrote it for something else, I added a monkey wrench and a screwdriver and it works for my needs, could it be better? Well you can judge for your self, it works good enough for my application as is
Thanks Once again Darrel for the post I extracated this code from.
Code:
@ DEVICE pic16F628A, HS_OSC
@ DEVICE pic16F628A, WDT_OFF
' Watchdog Timer
@ DEVICE pic16F628A, PWRT_ON
' Power-On Timer
@ DEVICE pic16F628A, MCLR_ON
' Master Clear Options (Internal)
@ DEVICE pic16F628A, BOD_OFF
' Brown-Out Detect
@ DEVICE pic16F628A, LVP_OFF
' Low-Voltage Programming
@ DEVICE pic16F628A, CPD_OFF
' Data Memory Code Protect
' Set to CPD_OFF for Development Copy
' Set to CPD_ON for Release Copy
@ DEVICE pic16F628A, PROTECT_OFF
' Program Code Protection
' Set to PROTECT_OFF for Development Copy
' Set to PROTECT_ON for Release Copy
trisb = %00000010
trisA = %11110011
include "modedefs.bas"
' Define LCD registers and bits
Define LCD_DREG PORTB
Define LCD_DBIT 4
Define LCD_RSREG PORTA
Define LCD_RSBIT 0
Define LCD_EREG PORTA
Define LCD_EBIT 1
DEFINE LCD_LINES 4 'Define using a 2 line LCD
DEFINE LCD_COMMANDUS 2000 'Define delay time between sending LCD commands
DEFINE LCD_DATAUS 50 'Define delay time between data sent.
DEFINE OSC 20
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER_SPBRG 32 ' FOR 20MHZ 129 = 2400, 32=9600,25 @ 4 for 2400
DEFINE HSER_CLROERR 1 ' Clear overflow automatically
RCIF VAR PIR1.5 ' Receive interrupt flag (1=full , 0=empty)
TXIF VAR PIR1.4 ' Transmit interrupt flag (1=empty, 0=full)
LED VAR PORTA.4
OERR VAR RCSTA.1 ' Alias OERR (USART Overrun Error Flag)
CREN VAR RCSTA.4 ' Alias CREN (USART Continuous Receive Enable)
buffer_size CON 64 ' Sets the size of the ring buffer, set up from 32
buffer VAR BYTE[buffer_size]' Array variable for holding received characters
index_in VAR BYTE ' Pointer - next empty location in buffer
index_out VAR BYTE ' Pointer - location of oldest character in buffer
bufchar VAR BYTE ' Stores the character retrieved from the buffer
i VAR BYTE ' loop counter
Col VAR BYTE ' Stores location on LCD for text wrapping
errflag VAR BYTE ' Holds error flags
index_in = 0
index_out = 0
i = 0
col = 1
'RxData var byte
CMCON = 7 ' PORTA is digital
Pause 100 ' Wait for LCD to startup
high PortA.2 ' power for backlight
low PortA.3 ' backlight ground
INTCON = %11000000 ' Enable interrupts
ON INTERRUPT GoTo serialin ' Declare interrupt handler routine
PIE1.5 = 1 ' Enable interrupt on USART
pause 1500
lcdout $FE,1
lcdout $FE,2
LCDOUT "Your Text Goes Here"
PAUSE 2000
' * * * * * * * * * * * * * Main program starts here - blink an LED at 1Hz
' I removed some code here, it seems to require what's left
loop:
For i = 0 to 10 ' Delay for .02 seconds (10*2mS)
Pause 2 ' Use a short pause within a loop
Next i ' instead of one long pause
For i = 0 to 10 ' Delay for .02 seconds (10*2mS)
Pause 2 ' Use a short pause within a loop
Next i ' instead of one long pause
display: ' dump the buffer to the LCD
IF errflag Then error ' Handle error if needed
IF index_in = index_out Then loop ' loop if nothing in buffer
GoSub getbuf ' Get a character from buffer
LCDOut bufchar ' Send the character to LCD
IF col > 20 Then ' Check for end of line
col = 1 ' Reset LCD location
LCDOut $fe,$c0,REP " "\20 ' Clear line-2 of LCD
LCDOut $FE,2 ' Tell LCD to return home
EndIF
GoTo display ' Check for more characters in buffer
' Subroutines
Disable ' Don't check for interrupts in this section
getbuf: ' move the next character in buffer to bufchar
index_out = (index_out + 1) ' Increment index_out pointer (0 to 63)
' Reset pointer if outside of buffer
IF index_out > (buffer_size-1) Then index_out = 0
bufchar = buffer[index_out] ' Read buffer location
Return
error: ' Display error message if buffer has overrun
IF errflag.1 Then ' Determine the error
LCDOut $FE,$c0,"Clearing Display Buffer" ' Display buffer error on
' line-2 and 3 Buff overrun
Else
LCDOut $FE,$D4,"USART Overrun" ' Display usart error on line-4
EndIF
LCDOut $fe,2 ' Send the LCD cursor back to line-1 home
For i = 2 to col ' Loop for each column beyond 1
LCDOut $fe,$14 ' Move the cursor right to the right column
Next i ' $14 = 20 DEC.
errflag = 0 ' Reset the error flag
CREN = 0 ' Disable continuous receive to clear overrun flag
CREN = 1 ' Enable continuous receive
GoTo display ' Errors cleared, time to work.
' * * * * * * * * * * * * * * * Interrupt handler
serialin: ' Buffer the character received
IF OERR Then usart_error ' Check for USART errors
index_in = (index_in + 1) ' Increment index_in pointer (0 to 63)
IF index_in > (buffer_size-1) Then index_in = 0 'Reset pointer if outside of buffer
IF index_in = index_out Then buffer_error ' Check for buffer overrun
HSerin [buffer[index_in]] ' Read USART and store character to next empty location
IF RCIF Then serialin ' Check for another character while we're here
Resume ' Return to program
buffer_error:
errflag.1 = 1 ' Set the error flag for software
' Move pointer back to avoid corrupting the buffer. MIN insures that it ends up within the buffer.
index_in = (index_in - 1) MIN (buffer_size - 1)
HSerin [buffer[index_in]] ' Overwrite the last character stored (resets the interrupt flag)
usart_error:
errflag.0 = 1 ' Set the error flag for hardware
Resume ' Return to program
End
As I gain coding experience I will revisit this code unless someone else does so first ;-)
JS
Oh, what I really like about this is you use the standard formatting commands as used with LCDOUT, no funky commands.
LCD serial backpacks
Serial in LCD out
Originally Posted by BobK
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