DS1307 Problems help please !!! :-)

[andybarrett1]

Hi Thank you for reading...

Using a 16f627

All I want to do is turn a light on at a time and turn it off a time later.... What am I doing wrong here.

Turns on OK but sees to add 4mins to the turn off time... Also randomly turns on !

Help please... Thank you for reading !

' Alias pins
            SDA Var PORTB.1
            SCL Var PORTB.2
            Light var PORTB.6 
        
' 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
        
'Set initial time 
            RTCYear = $18
            RTCMonth = $09
            RTCDate = $18
            RTCDay = $03
            RTCHour = $00
            RTCMin = $00
            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]
            Return

' Main program loop 
        
mainloop:   Gosub gettime        ' Read the time from the RTC
            IF (RTCHour=$00) and (RTCMin=$01) Then Light_On ' Light on
            IF (RTCHour=$00) and (RTCMin=$02) Then Light_Off ' Light off
            Pause 500            ' Do it about 2 times a min
            Goto mainloop        ' Do it forever and ever and ever
        
        
        
Light_On:   high Light
            return 
            
Light_Off:  Low light
            return             
            
        
       
   End

[sayzer]

  
mainloop:   
            Gosub gettime        ' Read the time from the RTC

            IF (RTCHour=$00) and (RTCMin=$01) Then 
                 Gosub Light_On ' Light on
            ENDIF

            IF (RTCHour=$00) and (RTCMin=$02) Then 
               Gosub Light_Off ' Light off
            ENDIF

            Pause 500            ' Do it about 2 times a min

            Goto mainloop        ' Do it forever and ever and ever
        
        
        
Light_On:   high Light
            return 
            
Light_Off:  Low light
            return             
            
        
       
   End

[Scampy]

I tend to convert the time from the RTC chip into two variables such as timeH and timeM for hours and minutes

I2CRead SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour,RTCWDay,RTCDay,RTCMonth,RTCYear,RTCCtrl]  ; read DS1307 chip

timeH=(RTCHour>>4)                                                  'convert the BCD format of the hours register and store in variable timeH
timeH=(timeH &$03)*10
timeH=timeH+(RTCHour&$0F)

timeM=(RTCMin>>4)
timeM=(timeM &$07)*10
timeM=timeM+(RTCMin&$0F)                                            'convert the BCD format of the mins register and store in variable timeM

And then its a simple matter to match values with other variables to turn lights on or off

lightsetHR = 14                         ' Set lights to come on at 2pm
lightsetMN = 00  

lightoffHR = 22                         ' Set lights to go off at 10pm
lightoffMN = 00

You could then used a simple logic routine like

If timeH >= lightsetHR and timeM>=lightsetMN then turn the lights on
If timeH < lightsetHR and timeM < lightsetMN or timeH>=lightoffHR and timeM>=lightoffMN then turn lights off

Or an alternative is to use a counter that resets at midnight. This only works where you need to turn the light on and off between 00:01 and 23:59 in the same day. This basically counts the minutes in a 24 hour period since midnight

I2CRead SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour]   ' read the RTC
	
timeH=(RTCHour>>4)                        'convert the BCD format of the hours register and store in variable timeH
timeH=(timeH &$03)*10
timeH=timeH+(RTCHour&$0F)

timeM=(RTCMin>>4)                         'convert the BCD format of the mins register and store in variable timeM
timeM=(timeM &$07)*10
timeM=timeM+(RTCMin&$0F)                     

Counter1 = (TimeH *60)+ TimeM             'take hours and multiply it by 60 then add odd minutes to get the total minutes into counter1

Then use if/then statements to match the on / off times to the counter value to turn on / off the light

If Counter1 => OnTime and counter1 < OffTime then                     ' check to see if the time in minutes since midnight matches the on time
pin made high to turn light on                                                       ' insert the routine to make the pin high and turn the light on
endif                                                                           
If Counter1 => OffTime or Counter1 < Ontime then                      ' check to see if the time in minutes since midnight matches the channel off time
pin made low to turn lamp off                                                  ' insert the line to make the pin low and turn the light off

I've used both options in various projects and both work within the limitations described above.

Hope that helps

[andybarrett1]

Thank you Both

Both your replies have been implemented now I am running again..... Always have problems with the If/Then/Next Endif stuff :-)

Thank you again

BR
Andy

[Scampy]

Glad it helped. My solutions may not be the most elegant, but it worked for me... and as all things in life there is always more than one solution