# Clock Accuracy

I recently completed a project to build a binary clock that basically uses the count function to keep time. The counter is easily tweaked to compensate for the run time of the program to make the clock more accurate, but I was wondering if I would be better off incorporating an IC555 chip to handle the timing function?

By "easily tweaked" I think you are kidding yourself. One of the causes of inaccuracy is temperature variations, and you can be tweaking for that for ever. If you want to use the word "accuracy" you should seriously consider a \$3 RTC like everybody else does. I don't know what a binary clock is but the DS3231 has a square wave output which may be just what you need, without bothering with all that tell-the-time stuff.

Scarebird:
I recently completed a project to build a binary clock that basically uses the count function to keep time. The counter is easily tweaked to compensate for the run time of the program to make the clock more accurate, but I was wondering if I would be better off incorporating an IC555 chip to handle the timing function?

If you get the Arduino with an actual crystal and pick one out with a more accurate timing and then insulate the board so temperature changes are minimized, you will get a more accurate clock.

But if you think using a 555 with timing based on a resistor and a capacitor, you are going the wrong way!

What accuracy do you want and how much time and \$ are you willing to spend on the project?

Paul

Paul_KD7HB:
If you get the Arduino with an actual crystal and pick one out with a more accurate timing and then insulate the board so temperature changes are minimized, you will get a more accurate clock.

But if you think using a 555 with timing based on a resistor and a capacitor, you are going the wrong way!

What accuracy do you want and how much time and \$ are you willing to spend on the project?

Paul

It's only a very basic project, so it's not worth throwing a lot of cash at it. Current accuracy is probably in the order of +/- 1 sec per day, and I hadn't considered that temperature might play a part in how an Arduino performs when using it to keep time.

An RTC module might be the answer, but the clock I have built uses a custom PCB, and is a tight fit in the cae it is housed in, so may cause more problems than it solves.

As it is just a small project, maybe I will have to live with it's inherrant faults.