Data from DS1307 (BCD) saved to ext memory and read back to display

[Scampy]

Hi Roger, I'm no expert, but maybe this can be of some use.

I have these variables to display the time on an LCD

TimeH           var byte                 'variable to store Hours
TimeM           var byte                 'variable to store Minutes
SS              VAR Byte                 'variable to store Seconds

RTCsec          var byte                'RTC Seconds
RTCMin          var byte		        'RTC Minutes
RTCHour         var byte	            'RTC Hours

I then read the DS1307 and convert the BDC value into time as follows

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)    

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

LCDOut $FE,$C0+11,#TimeH DIG 1,#TimeH DIG 0,":",#TimeM DIG 1,#TimeM DIG 0          'display the current time on the LCD

Now maybe (I don't know as I've never written to an external e-prom) you can save the byte variables for TimeH, TimeM and SS with something like

I2Cwrite SDApin,SCLpin,$insert address of eeprom,[TimeH,TimeM,SS]

Like I said, I'm no expert, and may be sending you off on a tangent !!

Forgot to add, this is the routine to convert to BDC if required

CounterA=SetMN
Gosub ConvertBCD
RTCMin=CounterB

CounterA=SetHR
Gosub ConvertBCD
RTCHour=CounterB
I2Cwrite SDApin,SCLpin,$D0,$00,[RTCSec,RTCMin,RTCHour]


ConvertBCD:
	CounterB=CounterA DIG 1                        ' CounterA is the entry variable
	CounterB=CounterB<<4                           ' CounterB holds the converted BCD result on exit
	CounterB=CounterB+CounterA DIG 0
Return

CounterA and CounterB are byte variables, as are setHR and setMN. I used these as the initial time to display on the LCD. For example I want to set the initial time to 12:00 I use 12 for setHR and 0 for setMN. If you need to convert from decimal to BDC before sending to the eepprom, then maybe this bit of code can help ??