Post by thread:[PIC]: DS1305 Real Time Clock?

Hi, I am implementing a PIC to communicate with a Dallas1305 real time clock in one of my projects. I can not get the clock to start.... Every time I read the clock I get zero for hours, minutes, seconds.... Where can I find some mpasm code samples? Must I start the chip some how after I have write the correct time to it? Regards Francois -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use spam_OUTlistservTakeThisOuTmitvma.mit.edu?body=SET%20PICList%20DIGEST>

At 10:51 AM 28/08/00 +0200, you wrote: >Hi, I am implementing a PIC to communicate with a Dallas1305 real time clock >in one of my projects. > >I can not get the clock to start.... > >Every time I read the clock I get zero for hours, minutes, seconds.... > >Where can I find some mpasm code samples? >Must I start the chip some how after I have write the correct time to it? > >Regards >Francois On page 7 of the PDF it says the oscillator control bit is undefined on initial powerup. You must check (set) this as part of your initialisation code in your PIC. Regards... -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use .....listservKILLspam@spam@mitvma.mit.edu?body=SET%20PICList%20DIGEST>

From data sheet: " Please note that the initial power on state of all registers in not defined. Therefore it is important to enable the oscillator (EOSC = 0) and disable write protect (WP = 0) during initial configuration. " Remove write protect and do some test writes. If you cant read write you probably have a software problem or need to read data sheet again. Are you bit banging or using PIC hardware for serial? If bit banging its not surprising to have some problems. Another thing that looks like it could make problems: " The DS1305 offers an important feature in that the level of the inactive clock is determined by sampling SCLK when CE becomes active. " Maybe you are forgetting to release chip select somewhere? Make sure you are using a _high_ chip select. We got this wrong where I used to work and all other serial devices stopped working. Whoa that was scary... Francois Robbertze wrote: {Quote hidden}> > Hi, I am implementing a PIC to communicate with a Dallas1305 real time clock > in one of my projects. > > I can not get the clock to start.... > > Every time I read the clock I get zero for hours, minutes, seconds.... > > Where can I find some mpasm code samples? > Must I start the chip some how after I have write the correct time to it? > > Regards > > Francois > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > use listservKILLspammitvma.mit.edu?body=SET%20PICList%20DIGEST -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use .....listservKILLspam.....mitvma.mit.edu?body=SET%20PICList%20DIGEST>

Hi When I found my mistake yesterday I was shocked...... My configuration was Ok Sometimes one try to look to deep into a problem!!!! I thought that my timing writing to the RTC was out and that is why I did not get any responce from the RTC So pin. Someone told me to check the voltage on Vccif!!!! And to my dissapointment found that I neglect to connect it. Lesson one: Read the data tables carefully!!! Thanks all Regards Francois > Hi, I am implementing a PIC to communicate with a Dallas1305 real time clock {Quote hidden}> in one of my projects. > > I can not get the clock to start.... > > Every time I read the clock I get zero for hours, minutes, seconds.... > > Where can I find some mpasm code samples? > Must I start the chip some how after I have write the correct time to it? > > Regards > > Francois -- http://www.piclist.com hint: PICList Posts must start with ONE topic: "[PIC]:" PIC only "[EE]:" engineering "[OT]:" off topic "[AD]:" ad's