Post by thread:Using a PIC16C5x as an accurate time reference?

I am designing a device that maintains an internal accurate clock, that also tracks the day of week. On weekdays at a certain time, I want to run a sequence that activates the power and channel buttons on a gutted remote control aimed at my television to turn it on, and off in an hour so I can wake up to television. I was wondering if a crystal controlled PIC 16C5X could be used as an accurate time reference. Neil Gandler

NEIL GANDLER wrote: > > I am designing a device that maintains an internal accurate clock, > that also tracks the day of week. On weekdays at a certain time, > I want to run a sequence that activates the power and channel buttons > on a gutted remote control aimed at my television to turn it on, and off > in an hour so I can wake up to television. I was wondering if a crystal > controlled PIC 16C5X could be used as an accurate time reference. > > Neil GandlerTry an NJU6355 serial clock chip available from Digikey for $1.68. I have designed a Basic Stamp add-on that works very well and should work as well with any PIC. Accuracy is obviously relative. Depending on the crystal you use with the 6355 and addition of external capacitance you can tune the accuracy. There is a method described in the app note to read the clock freq/256 out of the data pin so you can tinker with the equiv. capacitance. My experience is that accuracy is a few seconds/week, again depending on the crystal, heat and other nasty things, without this procedure. Anyway be sure to get the data sheets and app note. spam_OUTwthomasTakeThisOuTjorsm.com