Interrupts and Sleep help 16f818

Hi thank you for reading…

Using a 16f818/819

I am attempting to put something together that is asleep most of the time and only wakes up for a minute or so to read a display when a button is pressed…To save battery power.

I was thinking of using the ON INTERRUPT command on RB0 , And @SLEEP (the asm version, not the PicBasic Pro)

At the moment I am using the internal Pullups …(Option_Reg.7) … Some talk suggests issues on wakeup ?

I have no code yet as am looking for examples most of what I can find confuses me… I can do hardware but software is not easy !!

Any help / pointers welcome

Thank you for reading.

Hi,

Here is one way to do that ( Pic is a 18F2520 )

Code:

---



Sommeil:

        LCDOUT $FE,2, "BYE-BYE "

        For I = 8 to 0        Step -1                                        'Animation arret
       
                LCDOUT        $FE,$C0,REP "*"\I," "                        '        ...  4s                       
                PAUSE 500
               
        NEXT I
       
        PORTB.4        = 0                                        'Ports LCD à 0
        PORTB.5        = 0

        PORTC.7        = 0                                        ' PortC à 0
        PORTC.6        = 0
        PORTC.5        = 0
        PORTC.4        = 0       
       
       
        AlLCD                = 1                                        ' Coupure LCD
        AlRef                = 0                                        ' Coupure Vref       
        ADCON0.0        = 0                                        ' Désactivation ADC

       
        T3CON.0                = 0                                ' arret TMR3
        T1CON.0                = 0                                ' arret TMR1
        T0CON.7        = 0                                ' arret TMR0
       
        INTCON.7        = 0                        ' Wakeup sans interruptions
       
        INTCON3.0        = 0                                                ' reset flag INT1
        INTCON3.3        = 1                        ' validation INT1 pour réveil

        Alim                = 0                        'Coupure alimentation
        Signal                = 0                        'Extinction voyant régime
                               
@ SLEEP
@ Nop                                                ' Redémarrage par mise du contact sans coupure générale
                                                        ' Arret par décharge capa alim.

       
        INTCON3.3        = 0                        'Neutralisation INT1
        INTCON3.0        = 0                        'Reset Flag INT1
        Alim                = 1                        'Remise alimentation si remise contact rapide.
       
'*****************************************************************************
Wakeup: 'Début du Programme - reveil du PIC / Affichage Memoire
'*****************************************************************************
'
FLAGS        = 0                                        ' Validation Reset LCD

        PORTB.4 = 0                                        'Ports LCD à 0
        PORTB.5 = 0

        PORTC.7 = 0                                        ' PortC.4-7 à 0
        PORTC.6 = 0
        PORTC.5 = 0
        PORTC.4 = 0
       
Reveil        = 1
LSelect        = 0
       
GOTO Load                                'Rechargement mémoires et Affichage de Départ

---

Here, the processor stops and restarts @ the line after the "@Sleep" command, because GIE bit has been disabled.
The @NOP is highly recommended here ...

IF GIE is not disabled , processor will jump to the Interrupt stubb ...

Alain

Merci Alain.

I'm keeping a link to this thread.

Robert
:)

Hello again...

Have put together some code as I see it... :-

Code:

---

' Name        : PI.pbp
' Compiler    : PICBASIC PRO Compiler 2.5
' Assembler  : MPASM
' Target PIC  : PIC16F628A or similar type
' Hardware    : VeroBoard
' Oscillator  : 4Megs Internal
' Keywords    : I2CREAD, I2CWRITE, LCDOUT
' Description : PICBASIC PRO program for an LCD clock program
' using the Dallas DS1307 I2C RTC.


' Define LCD pins
        DEFINE LCD_EREG PORTA
        DEFINE LCD_EBIT 6

' Alias pins
        SDA Var PORTB.1
        SCL Var PORTB.4
        wakebutton var PORTB.0 'shake
        lcdandrtc var PORTA.6 'LCD and RTC ON/OFF
        timeout1 var byte
        'timeout2 var byte
       
       

' Allocate variables
        RTCYear  Var Byte
        RTCMonth Var Byte
        RTCDate  Var Byte
        RTCDay  Var Byte
        RTCHour  Var Byte
        RTCMin  Var Byte
        RTCSec  Var Byte
        RTCCtrl  Var Byte
   
        TRISA=0 'outputs
        TRISB=15 'Bit 0,1,2,3 inputs
        CMCON=7 'turns  off analogs
wakeup: INTCON=%00010000 'RB0 is interrupt
        OPTION_REG.6=0 'Trig on falling
        OPTION_REG.7=0 'Enables pull ups     
        Pause 500            ' Wait for LCD to startup
        Lcdout $fe, 1 ' Clear LCD screen
        Lcdout "WELCOME TO"  ' Display WELCOME TO
        Lcdout $fe, $C0, "      PI DAY" ' Display  PI Day
        Pause 2000      ' Wait 2 seconds
        Lcdout $fe, 1 ' Clear LCD screen
       
        'Set initial time
        RTCYear = $15
        RTCMonth = $03
        RTCDate = $03
        RTCDay = $06
        RTCHour = $20
        RTCMin = $46
        RTCSec = 0
        RTCCtrl = 0
        'Gosub settime        ' Set the time
        Goto mainloop        ' Skip over subroutines

' Subroutine to write time to RTC

'settime:I2CWrite SDA, SCL, $D0, $00, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear, RTCCtrl]
'        Return

' Subroutine to read time from RTC
       
gettime:I2CRead SDA, SCL, $D0, $00, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear, RTCCtrl]
        timeout1=rtcmin
        Return

' Main program loop
       
mainloop:Gosub gettime        ' Read the time from the RTC

        ' Display time on LCD
        'Lcdout $fe, 1, hex2 RTCMonth, "/", hex2 RTCDate, "/" , hex2 RTCYear,_
        '"  ", hex2 RTCHour, ":", hex2 RTCMin, ":", hex2 RTCSec

        Lcdout $fe, 1, HEX2 RTCDate, "/", HEX2 RTCMonth,"  ", HEX2 RTCHour, ":", HEX2 RTCMin, ":", HEX2 RTCSec
       
        IF RTCHour <=$12 then  gosub morning
        IF RTCHour >=$13 then  gosub afternoon
       
        IF RTCHour=$03 and RTCMin=$14 Then CACHE ' Morning Cache
        IF RTCHour=$15 and RTCMin=$14 Then CACHE ' Afternoon Cache
       
       
        if rtcmin=(timeout1+2) then bedtime
       
        Pause 500            ' Do it about 2 times a second
        Goto mainloop        ' Do it forever
       
morning:    Lcdout $fe, $C0, "CACHE @  3:14AM"
        return
       
afternoon:  Lcdout $fe, $C0, "CACHE @ 3:14PM"
        return
       
CACHE:  Lcdout $fe, 1 ' Clear LCD screen
        LCDOUT "CONGRATULATIONS"
        Lcdout $fe, $C0, "CACHE IS LOCATED"
        PAUSE 2000
        Lcdout $fe, 1 ' Clear LCD screen
        Lcdout "N  XX",$DF, "  YY.ZZZ "  ' Display N  123° 456.789
        Lcdout $fe, $C0, "W  XX",$DF, "  YY.ZZZ " ' Display  W  123° 456.789
        PAUSE 20000
       
bedtime:high lcdandrtc 'turn of lcd and rtc
        INTCON.1=0 'reset RB0 interupt flag
        @ sleep
        @ NOP
        @ NOP
        pause 500 'wakeup delay
        goto wakeup
       
        end

---

Would appreciate some comments .... good or bad on above code.... I am not really sure about my jumps out of the main loop to "bedtime" I have just identified that if it is more than 58 mins to the hour my +2 calc wont work :-) So need to find a work around ?

Thank you for reading... Andy

Andy,

You are correct that your timeout1 test/calculation will fail when the RTC roles over from 59 to 00.
Also, if for some reason that the execution is delayed you could miss an entire minute which would further affect your timeout1 test.

I took the liberty of adding/modifying the logic to make this portion more robust (although I can't test this :-) )
Take a look at the revised code and see if this helps you.

Code:

---

' Name        : PI.pbp
' Compiler    : PICBASIC PRO Compiler 2.5
' Assembler  : MPASM
' Target PIC  : PIC16F628A or similar type
' Hardware    : VeroBoard
' Oscillator  : 4Megs Internal
' Keywords    : I2CREAD, I2CWRITE, LCDOUT
' Description : PICBASIC PRO program for an LCD clock program
' using the Dallas DS1307 I2C RTC.


' Define LCD pins
        DEFINE LCD_EREG PORTA
        DEFINE LCD_EBIT 6

' Alias pins
        SDA Var PORTB.1
        SCL Var PORTB.4
        wakebutton var PORTB.0 'shake
        lcdandrtc var PORTA.6 'LCD and RTC ON/OFF
        timeout1 var byte
        'timeout2 var byte
        PrevTime var byte    'Holds previously read RTCMin
        CurTime  var byte    'Holds currently read RTCMin
        TimeoutMax var byte 'You can change this to a constant if it is not changed during execution
        WakeupFlag var bit    'Used for wakeup/reset tracking for timer
       
        TimeoutMax = $02    'You can delete this if TimeoutMax is a constant
        WakeupFlag = 1        'Preset to true
       
' Allocate variables
        RTCYear  Var Byte
        RTCMonth Var Byte
        RTCDate  Var Byte
        RTCDay  Var Byte
        RTCHour  Var Byte
        RTCMin  Var Byte
        RTCSec  Var Byte
        RTCCtrl  Var Byte
   
        TRISA=0 'outputs
        TRISB=15 'Bit 0,1,2,3 inputs
        CMCON=7 'turns  off analogs
       
       
       
wakeup: INTCON=%00010000 'RB0 is interrupt
        OPTION_REG.6=0 'Trig on falling
        OPTION_REG.7=0 'Enables pull ups     
        Pause 500            ' Wait for LCD to startup
        Lcdout $fe, 1 ' Clear LCD screen
        Lcdout "WELCOME TO"  ' Display WELCOME TO
        Lcdout $fe, $C0, "      PI DAY" ' Display  PI Day
        Pause 2000      ' Wait 2 seconds
        Lcdout $fe, 1 ' Clear LCD screen
       
       
        timeout1 = TimeoutMax  'Preset timeout1 for countdown
       
        'Set initial time
        RTCYear = $15
        RTCMonth = $03
        RTCDate = $03
        RTCDay = $06
        RTCHour = $20
        RTCMin = $46
        RTCSec = 0
        RTCCtrl = 0
        'Gosub settime        ' Set the time
        Goto mainloop        ' Skip over subroutines

' Subroutine to write time to RTC

'settime:I2CWrite SDA, SCL, $D0, $00, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear, RTCCtrl]
'        Return

' Subroutine to read time from RTC
       
gettime:I2CRead SDA, SCL, $D0, $00, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear, RTCCtrl]
        'timeout1=rtcmin
        CurTime = RTCMin    '
        if WakeupFlag = 1 then  '1st time after a wakeup/reset
            PrevTime = CurTime  'Set PrevTime after wakeup/reset
            WakeupFlag = 0        'Clear the flag
        endif
       
        Return

' Main program loop
       
mainloop:
        Gosub gettime        ' Read the time from the RTC

        ' Display time on LCD
        'Lcdout $fe, 1, hex2 RTCMonth, "/", hex2 RTCDate, "/" , hex2 RTCYear,_
        '"  ", hex2 RTCHour, ":", hex2 RTCMin, ":", hex2 RTCSec

        Lcdout $fe, 1, HEX2 RTCDate, "/", HEX2 RTCMonth,"  ", HEX2 RTCHour, ":", HEX2 RTCMin, ":", HEX2 RTCSec
       
        IF RTCHour <=$12 then  gosub morning
        IF RTCHour >=$13 then  gosub afternoon
       
        IF RTCHour=$03 and RTCMin=$14 Then CACHE ' Morning Cache
        IF RTCHour=$15 and RTCMin=$14 Then CACHE ' Afternoon Cache
       
       
        'if rtcmin=(timeout1+2) then bedtime
        If CurTime > PrevTime Then
            timeout1 = timeout1 - (CurTime - PrevTime)
            PrevTime = CurTime
        else
            'Oops something happened. Current time is less than Previous time
            'This should take care of the rollover from 59 to 00 minutes and unexpected delays
            'If timeout1 = 0 no need to do anything, the timeout1 test below will put the unit to sleep
            'The WakeupFlag will be set when we go to sleep and PrevTime and CurTime will be set properly
            'after we wakeup and proceed through the mainloop
            if timeout1 > 0 then
                timeout1 = timeout1 - 1 'decrement the timeout value
                PrevTime = CurTime  'Reset Previous time to a valid number for the countdown timer
            endif
        endif
       
        if timeout1 = 0 then    'Timeout reached
            WakeupFlag = 1    'Reset the flag
            goto bedtime        'countdown has reached 0, go to sleep
        endif
       
        Pause 500            ' Do it about 2 times a second
        Goto mainloop        ' Do it forever
       
morning:    Lcdout $fe, $C0, "CACHE @  3:14AM"
        return
       
afternoon:  Lcdout $fe, $C0, "CACHE @ 3:14PM"
        return
       
CACHE:  Lcdout $fe, 1 ' Clear LCD screen
        LCDOUT "CONGRATULATIONS"
        Lcdout $fe, $C0, "CACHE IS LOCATED"
        PAUSE 2000
        Lcdout $fe, 1 ' Clear LCD screen
        Lcdout "N  XX",$DF, "  YY.ZZZ "  ' Display N  123° 456.789
        Lcdout $fe, $C0, "W  XX",$DF, "  YY.ZZZ " ' Display  W  123° 456.789
        PAUSE 20000
       
bedtime:high lcdandrtc 'turn of lcd and rtc
        INTCON.1=0 'reset RB0 interupt flag
        @ sleep
        @ NOP
        @ NOP
        pause 500 'wakeup delay
        goto wakeup
       
        end

---

Missed this...

Thanks TABSoft..... Will try later.

Let you know how I get on

BR
Andy

Just had a play with this….

Sorted a few problems out around the sleep…. Still got issues jumping out of the main loop to go to sleep…But the sleep works !!

Andy,

You can encase your mainloop code in a Do/Loop While with a test of the WakeupFlag.
Then when the WakeupFlag is set at timeout, the loop will terminate and you can replace the "GOTO mainloop" instruction with a GOTO bedtime as the last instruction of mainloop.

Or

You can use a Do/Loop with an "Exit" statement in place of the "GOTO bedtime" instruction in the timeout1 If/Then test. Still replace the "GOTO mainloop" instruction with a "GOTO bedtime" instruction as the last instruction in mainloop.

Also, I overlooked the fact that you are jumping to CACHE twice a day and CACHE falls through to bedtime without setting the WakeupFlag. You shou set the WakeupFlag before you jump to CACHE.

What kind of problems are you having?

Idea in the night of using a FOR / NEXT loop with a IF / THEN / GOTO

Easy Fix ??

Wil try later !!!

FOR / NEXT Instruction worked…

One Cycle of my loop takes a .5 Seconds so :-

Timeout = 0 to 240
Code…
………..

Next Timeout
GOTO Label

Thank you for help

Andy

Thank you for reading

Just need to get the quiescent current down whist in sleep mode. Currently seeing around the 2mA mark.

I am hoping we can get it lower than that…?

Thank you for reading.

Andy