Nap and sleep commands

[FinchPJ]

Thanks for all your help Bruce - this is a followup to report that an external 32 KHz crystal and two 33 pF caps have sorted my sleep problems - for the record this works a dream:

    T1CON   =   %00001110

with a TMR1 interrupt (RTCupdate) of:

asm
TMR1Const = 8000h
ADD2_TMR1   macro
            BCF     T1CON,TMR1ON, 0     ; Timer OFF
            MOVLW   LOW(TMR1Const)      ; +1
            ADDWF   TMR1L,F, 0          ; +1
            BTFSC   STATUS,C            ; +1/2
            INCF    TMR1H,F, 0          ; +1
            MOVLW   HIGH(TMR1Const)     ; +1
            ADDWF   TMR1H,F, 0          ; +1
            endm
RELOAD_TMR1 macro
            ADD2_TMR1
            BSF     T1CON,TMR1ON, 0     ; +1=7 cycles overhead before Timer ON
            endm
LOAD_TMR1   macro
            MOVE?CT  0, T1CON,TMR1ON
            MOVE?CB  0, TMR1L
            MOVE?CB  0, TMR1H
            ADD2_TMR1
            endm
endasm
RTCupdate:
@      RELOAD_TMR1
       Seconds = Seconds + 1
       dSecs = 1
       if (Seconds < 60) then IHdone
       Minutes = Minutes + 1
       Seconds = 0
       if (Minutes < 60) then IHdone
       Hours = Hours + 1
       Minutes = 0
       if (Hours < 24) then IHdone
       Days = Days + 1
       Hours = 0
IHdone:                     'Restore context and RETFIE
@   INT_RETURN

and a sleep inducing routine of:

gosleep:
            lcdout $FE, $C0, "USB LP, SLEEP   "
            T0CON.7 = 0     ' Disable USBservice interrupts
@           INT_DISABLE TMR0_INT
@	        clrf	UCON	; Disable USB & detach from bus
@	        clrf	UIE  	; Mask all USB interrupts
lowpower:   IF dSecs = 1 THEN  
                dSecs = 0
                lcdout $FE, $02, "Time ", dec2 Hours, ":", dec2 Minutes, ":", dec2 Seconds, "   "
            ENDIF
            OSCCON.7 = 0     'Clear IDLEN - switch to SLEEP 
@           SLEEP
@           NOP
            goto lowpower

Peter

[FinchPJ]

Since our production circuit board has been professionally produced, there is not room for an extra Xtal and caps to drive TMR1 so I am trying to get the WDT to do the wake from sleep but with only partial success. In particular it doesnt seem to matter what I put as a postscaler value the WDT seems to cycle at a fixed period of around 578 mSec (suspiciously similar to Nap 5 frequency!). I am setting CONFIG2H by using this instead of the corresponding (commented out) line in 18F4550.INC:

asm
       __CONFIG    _CONFIG2H, _WDT_OFF_2H & _WDTPS_256_2H
;must comment out in 18F4550.INC, or change there, else duplicate error
endasm

and then:

            i = 0
lowpower:   lcdout $FE, $02, "WDT ", hex2 i, 
            i = i + 1
            ' Do all the other stuff here (read ADC, store to Mem) 
            clearwdt
            WDTCON = 1       'SWDTEN
'           OSCCON.7 = 0     'Clear IDLEN - switch to SLEEP 
            OSCCON.7 = 1     'Set IDLEN - switch to SEC_IDLE
@           SLEEP 
@           NOP  
            WDTCON = 0    ' WDT off
            goto lowpower

and i increments 128 in 74 secs (period = 578mSec), but different values of _WDTPS_1024_2H etc. make no difference. What am I missing here? It makes no difference whether I make the CPU sleep or idle (except to the current consumption 3 or 15 mA - most of the 3 lost in the 9v voltage regulator).
DEFINE NO_CLRWDT 1 makes no difference and the CLEARWDT also seems to make no difference!

I would like to have the ability to control the frequency as expected and am thinking I can sleep for most of the 1 second I want and fine tune with another timer while awake - PAUSE would be the simplest. Any ideas gratefully received!

Peter

PS It just occurs to me that I am using a Bootloader - could this mean that the Postscaler is set by the bootloader and not changed by my program - if so can I do anything to change this ??edit the bootloader somehow.

[Bruce]

Most bootloaders will not allow you to change config settings, but the Microchip USB loader will, or you can change WDT config settings at runtime.

See these threads:

http://www.picbasic.co.uk/forum/showthread.php?t=4093

http://www.picbasic.co.uk/forum/show...ghlight=config

Or just open the loader .HEX file, make your changes, save it, and reprogram the PIC with the new loader firmware.

[FinchPJ]

http://www.picbasic.co.uk/forum/showthread.php?t=4093

http://www.picbasic.co.uk/forum/show...ghlight=config

Now that is seriously helpful - Sorry I didnt spot those earlier on my searches - thank you so much for your help Bruce (and Darrel) - you are amazing!

Peter