DS1307 RTC - Advice please.

[malc-c]

I've just loaded this code and this too shows 00:00:00 for date and time

@   __config _HS_OSC & _WDT_ON & _LVP_OFF & _CP_OFF  ; use this for 16F877a

DEFINE  OSC 20
CLEAR

;----[LCD definitions]------------------------------------------------------
DEFINE LCD_DREG  PORTB              ' LCD Data port
DEFINE LCD_DBIT  0                  ' starting Data bit (0 or 4)
DEFINE LCD_EREG  PORTB              ' LCD Enable port
DEFINE LCD_EBIT  5                  ' Enable bit  (on EasyPIC 5 LCD)
DEFINE LCD_RSREG PORTB              ' LCD Register Select port
DEFINE LCD_RSBIT 4                  ' Register Select bit   (on EasyPIC 5 LCD)
DEFINE LCD_BITS  4                  ' LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 2                  ' number of lines on LCD
DEFINE LCD_COMMANDUS 2000           ' Command delay time in us 
DEFINE LCD_DATAUS 50                ' Data delay time in us 

SDA var PORTC.4                     ' RTC data 
SCL var PORTC.3                     ' RTC clock

TRISC= %11111111
DB0 var byte[8]
CMCON = %00000111                   ' Comparators = off
gosub write_1307
read_1307:                          ' Read time Secs,Mins,Hours,Day,Date,Month,Year,Control
I2CREAD SDA,SCL,$D1,$00,[STR DB0\8] ' Read 8 bytes from DS1307

lcdout $fe,1,"Time=",hex2 DB0[2],":",hex2 DB0[1],":",hex2 DB0[0]    'bit 0=sec, bit 1=min, bit 2=hrs
lcdout $fe,$c0,"Date=",hex2 DB0[4],":",hex2 DB0[5],":",hex2 db0[6]  'bit 4=day, bit 5=month, bit 6=year
goto read_1307
end

Write_1307:                          ' Set time & date to 19:00:00  14th Feb 201
I2CWRITE SDA,SCL,$D0,$00,[$00,$00,$19,$7,$14,$2,$10,$90] ' Write to DS1307
pause 10
RETURN                               ' Sec Min Hr Day D M Y Control

Guess the module is faulty

[malc-c]

I've sussed it !

Some time ago I was using an 18F4550 which was set for USB comms



Whilst I had scoured the data sheet I forgot that on the 18F4550 RC3 and RC4 are used for USB comms - a R of TFM has resolved the issue....

Hours of frustration..... ERRRRR !

Life's a learning curve !