This is a continuation of this post Using the PIC16F690’s (and others’) Internal Timers to Keep Time
We are not using a crystal or an RTC for this digital clock!!! This is just a demonstration of the internal timers and is not intended to keep actual time.
So, since we aren’t using an RTC, and we are using just a simple internal RC oscillator embedded in our PIC16F690, what kind of accuracy are we looking at? Well, if you are a perfectionist, than stop reading!!! This will not compete with your Seiko (You’ll see why I said that soon). It can’t compete with the DS1305. What it can do is make a somewhat accurate clock at half the cost and half the soldering(maybe) and half the programming and half… I think you might see my point of why this is a cool project. We all have cell phones and computers that have Atomic timekeeping or something, but who has an Altoids clock? Or whatever you decide to do with it? If you can initial off on the “not perfect” line, please continue. (I’ll explain how inaccurate this thing is in just a few paragraphs)