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

[flotulopex]

Address should be word or byte variable, not constant.

Okay, I haven't declared the address as a variable at all.

So I'll give it a try a little later (I'm in the office right now).

...your external eeprom is expecting 16 bit values for the data.

This is confusing me. I think the 24LC64 needs data in BYTE format as where it's addresses are in WORD format.

[Dave]

That is correct. The 24LC64 data is 8 bits wide per individual location. CH1_PWM.lowbyte,CH1_PWM.highbyte is the correct way to sequentially load data into the eeprom if the variable is a word.

[flotulopex]

It works!

I declared the EEPROM address as WORD, replaced the $00 in the I2CWRITE and I2CREAD commands and now the result is okay.

Thanks a lot for the help

'-------------------------------------------------------------------------------
' PIC 16F690 Fuses (MPASM)
@ __Config _FCMEN_OFF &_IESO_OFF &_CPD_OFF &_WDT_OFF &_HS_OSC &_BOR_OFF &_CP_OFF &_PWRTE_OFF &_MCLRE_OFF 

'-------------------------------------------------------------------------------
' Registers   76543210
OPTION_REG = %10000000 'PORT A&B Pull-Ups disabled (look WPUA & WPUB) INTEDG rising edge on A2
'OSCCON     = %01100000 'Internal RC set to 4Mhz - not to be used with XTal
ANSEL      = %00000000 'Analog inputs Channels 0 to 7
ANSELH     = %00000000 'Analog inputs Channels 8 to 11
ADCON0     = %00000000 'A/D Module is OFF
CM1CON0    = %00000000 'Comparator1 Module is OFF
CM2CON0    = %00000000 'Comparator2 Module is OFF
INTCON     = %00010000 'INTerrupts CONtrol
TRISA      = %00000100 'Set Input/Output (0 to 5)
PORTA      = %00000000 'Ports High/Low (0 to 5)
TRISB      = %00010000 'Set Input/Output (4 to 7)
PORTB      = %00000000 'Ports High/Low (4 to 7)
TRISC      = %00000000 'Set Input/Output (0 to 7)
PORTC      = %00000000 'Ports High/Low (0 to 7)

'-------------------------------------------------------------------------------
' Defines
DEFINE OSC 4

'-------------------------------------------------------------------------------
' Variables
SQW     VAR PORTA.2 ' RTC 1Hz output
D_Out   VAR PORTB.7 ' serial data out
SCL     VAR PORTC.0 ' RTC clock
SDA     VAR PORTC.1 ' RTC data 

RTC_Sec VAR BYTE    ' Seconds (00-59)
RTC_Min VAR BYTE    ' Minutes (00-59)
RTC_Hou VAR BYTE    ' Hours (00-23)

Eep_Adr VAR WORD
Eep_Adr = $00

D_Bps   CON 16468   ' 9600 Driven Inverted None

'-------------------------------------------------------------------------------
' Initialize
PAUSE 1000                      ' power-up serial-LCD
SEROUT2 D_Out,D_Bps,[27,"C",0]  ' set serial-LCD cursor OFF
SEROUT2 D_Out,D_Bps,[27,"L",0]  ' set serial-LCD backlight OFF

'-------------------------------------------------------------------------------
' Program
ON INTERRUPT GOTO Read_DS1307

MAIN:
    GOTO MAIN:
END    

'-------------------------------------------------------------------------------
' Interrutp Service Routine
DISABLE
Read_DS1307:
    I2CREAD SDA,SCL,$D1,$00,[RTC_Sec,RTC_Min,RTC_Hou]

    SEROUT2 D_Out,D_Bps,["HEX: ",HEX2 RTC_Hou,":",HEX2 RTC_Min,":",HEX2 RTC_Sec,13,10]

    ' Convert Hex coded to decimal - can be usefull for external memory data storage (logging)
    RTC_Sec = (RTC_Sec & $F)+((RTC_Sec >> 4)*10)
    RTC_Min = (RTC_Min & $F)+((RTC_Min >> 4)*10)
    RTC_Hou = (RTC_Hou & $F)+((RTC_Hou >> 4)*10)

    ' Write to external memory
    I2CWRITE SDA,SCL,$A0,Eep_Adr,[RTC_Sec,RTC_Min,RTC_Hou]
    PAUSE 10
    
    'Read from external memory
    I2CREAD SDA,SCL,$A0,Eep_Adr,[RTC_Sec,RTC_Min,RTC_Hou]

    SEROUT2 D_Out,D_Bps,["DEC: ",DEC2 RTC_Hou,":",DEC2 RTC_Min,":",DEC2 RTC_Sec,"   "]

    INTCON.1 = 0  'clear INTF interrupt flag
    RESUME 
ENABLE

Thank you Dave for explaining the WORD sized eeprom data.

Before I started this thread, I didn't know about "packed BDC". I think it can be interesting to reduce data size especially when, like in my current project, time data has to be stored in external memory.