DS1307 not running?

[EarlyBird2]

Richard,

The control and Address are wrong in the I2C instructions. Control should be $0 if not using the SQWO. The address should be $D0 for write and $D1 for read. Or that is the way I interpret the data sheet.

[richard]

the ds1307 has 8 registers for the rtc function addressed from 0 to 0x07
the control reg address is 0x07 bits 7 and 4 control the sqwe , if you only use the time keeping function the control reg can be ignored
to set the time you start at register address 0 (sec min hours ......)
to read just minutes start from address 1 etc
pbp will set bit 0 of the device address ($d0 in this case) as required (at least pbp3 will not sure about pbp2xx)

the ram goes from 0x08 to 0x3f trying to write or read from regs $d0 or $d1 will not have meaning full results

[EarlyBird2]

Richard,

Now I understand the datasheet refers to the control as address, how confusing. I did not realise that the eighth bit is added automatically.

Thanks for that.

[EarlyBird2]

Having read the data sheet again I found this near the end



How confusing that makes us both wrong. I must learn to read the whole data sheet in future.

[EarlyBird2]

Check this link

http://www.picbasic.co.uk/forum/showthread.php?t=12671

[richard]

I will say again pbp will set bit 0 of the i2c device address as required
by running :-
I2CRead SDA, SCL, $D0, 0, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear]

it will write 0 to the control address logic of the 1307 and then read 7 bytes
try it !

[EarlyBird2]

I will say again pbp will set bit 0 of the i2c device address as required
by running :-
I2CRead SDA, SCL, $D0, 0, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear]

it will write 0 to the control address logic of the 1307 and then read 7 bytes
try it !

$D0 is write

I2CRead SDA, SCL, $D1, 0, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear]

Is read according to the data sheet and the example in #9.

Interestingly the data sheet extract shown in #8 says to do

I2CWrite SDA, SCL, $D0, 0

reset the write pointer then

I2CRead SDA, SCL, $D1, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear]

to read the time.

But the example code in #9 works by using

I2CRead SDA, SCL, $D1, 0, [RTCSec, RTCMin, RTCHour, RTCDay, RTCDate, RTCMonth, RTCYear]

So I am curious to find out from Sabahan what works in his case.