18F4580 settings

[Bruce]

Config options and definitions vary from one device type to the next, so you can't always get away with cut & paste config options.

Just look in the P18F4580.INC file in your MPASM directory for a complete list of options available for each device type.

[malc-c]

Bruce, to be honest I don't have the understanding of these devices to really appreciate the info in that INC file...

Here's my logic... for what its worth.

The attached code works with a DS1307 module when using a 16F877A with just two small changes, namely the config settings are set to

@   __config _HS_OSC & _WDT_ON & _LVP_OFF & _CP_OFF

And the OSC value set to 20

I swapped the PIC for an 18F4580, changed the OSC value to 48 and the config settings to

ASM 
;  __CONFIG    CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L
;  __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H
  __CONFIG    _CONFIG2L, _PWRT_ON_2L  
  __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
  __CONFIG    _CONFIG3H, _PBADEN_OFF_3H
  __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L
ENDASM

It compiles with no errors, loads into the PIC, but the LCD is blank. Both chips used RC3 and RC4 for the Ic2 (SCL and SDA) and I've tried changing OSC to 20 instead of 48 but it still fails to display anything (even garbage) on the LCD.

Why is life so difficult.... !

[malc-c]

Well the PIC's working with those settings - I went back to basics and wrote the following simple basic "hello world" type code.

ASM  ; 18F2550/4550, 20mhz crystal
;  __CONFIG    CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L
;  __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H
  __CONFIG    _CONFIG2L, _PWRT_ON_2L  
  __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
  __CONFIG    _CONFIG3H, _PBADEN_OFF_3H
  __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L
ENDASM

DEFINE  OSC 48

clear

;----[LCD definitions]------------------------------------------------------
DEFINE LCD_DREG  PORTB          ' LCD Data port
DEFINE LCD_DBIT  0              ' starting Data bit (0 or 4)
DEFINE LCD_EREG  PORTB          ' LCD Enable port
DEFINE LCD_EBIT  5              '     Enable bit  (on EasyPIC 5 LCD)
DEFINE LCD_RSREG PORTB          ' LCD Register Select port
DEFINE LCD_RSBIT 4              '     Register Select bit   (on EasyPIC 5 LCD)
DEFINE LCD_BITS  4              ' LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 4              ' number of lines on LCD
DEFINE LCD_COMMANDUS 2000       ' Command delay time in us 
DEFINE LCD_DATAUS 50            ' Data delay time in us

;---------------------------------------------------------------------------

	
counter var byte
for counter = 1 to 10
LCDOut $FE,2,"Number = ",dec counter
pause 10
next

This displays "Number = " and counts from 1 to 10 on the LCD

I've looked at the datasheet, but can't see anything obvious other than making the correct pins on Port C input or outputs (something I would of thought would of ported over from the code)

Any suggestions

[malc-c]

Well expanding on the first test I now have data being read from the RTC module

ASM  ; 18F2550/4550, 20mhz crystal
;  __CONFIG    CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L
;  __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H
  __CONFIG    _CONFIG2L, _PWRT_ON_2L  
  __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
  __CONFIG    _CONFIG3H, _PBADEN_OFF_3H
  __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L
ENDASM

DEFINE  OSC 48

clear

;----[LCD definitions]------------------------------------------------------
DEFINE LCD_DREG  PORTB          ' LCD Data port
DEFINE LCD_DBIT  0              ' starting Data bit (0 or 4)
DEFINE LCD_EREG  PORTB          ' LCD Enable port
DEFINE LCD_EBIT  5              '     Enable bit  (on EasyPIC 5 LCD)
DEFINE LCD_RSREG PORTB          ' LCD Register Select port
DEFINE LCD_RSBIT 4              '     Register Select bit   (on EasyPIC 5 LCD)
DEFINE LCD_BITS  4              ' LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 4              ' number of lines on LCD
DEFINE LCD_COMMANDUS 2000       ' Command delay time in us 
DEFINE LCD_DATAUS 50            ' Data delay time in us

;---------------------------------------------------------------------------


RTCYear	Var	Byte
RTCMonth Var Byte
RTCDate	Var	Byte
RTCDay	Var	Byte
RTCHour	Var	Byte
RTCMin	Var	Byte
RTCSec	Var	Byte
RTCCtrl Var	Byte

SDA	Var	PORTC.4
SCL	Var	PORTC.3

main:
I2CRead SDA,SCL,$D0,$00,[RTCSec,RTCMin,RTCHour,RTCDay,RTCDate,RTCMonth,RTCYear,RTCCtrl]
Lcdout $fe, 2,hex2 RTCDate, "/",hex2 RTCMonth, "/" , hex2 RTCYear,_
		"  ", hex2 RTCHour, ":", hex2 RTCMin, ":", hex2 RTCSec
goto main:

So now just have to work out why the original code that worked with the 16F877A didn't / doesn't port across ?

[Bruce]

Hi Malcolm,

Read this thread. http://www.picbasic.co.uk/forum/showthread.php?t=543

If you're still stuck let me know.

[malc-c]

Bruce,

Thanks for the reply. I've managed to port Mel's RTC code from the 16F877A to the 18F4580, however I have one config setting that I can't work out

If I set the config bits in the programmer thus



The code runs. However if I let the code set the config bits it fails to run correctly. It seems I need to set the Oscillator to HS-PPL in order for it to run at the correct speed. Could you advise me what I need to add to the code to set this correctly ?

Edit:

Forgot to mention I've tried

__CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H

and get the "symbol not previously defined" error, even though I've edited the PBP INC file.

[malc-c]

Uhmmm steep learning curve

I delved deep into that INC file in MPSAM folder and tried the following

ASM  
  __CONFIG    _CONFIG1H, _OSC_HSPLL_1H
  __CONFIG    _CONFIG2L, _PWRT_ON_2L  
  __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
  __CONFIG    _CONFIG3H, _PBADEN_OFF_3H
  __CONFIG    _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L
ENDASM

Works fine now !