Ice tube and chronodot?

[Npkeith]

Help out a (relative) noob here. My Ice tube was probably the most complex kit i've ever made. I love it, but it keeps lousy time, gaining a couple of minutes a week. I've heard about this chronodot from a few places, and that its ultra accurate. Is there a simple mod to just splice one in at the right spot, or do I have to do a major rewire and reprogram? If is the latter, I'm willing to try, but I'll have to buy and build a programmer (and probably start with the photosensor dimmer mod.)

So. How do I do this?

[adafruit_support_bill]

The chip on the Chronodot is compatible, but the form-factor of the Chronodot board is different.

Check the last post in this topic: http://forums.adafruit.com/viewtopic.php?f=41&t=15020&p=73783&hilit=chronodot#p73783

[Npkeith]

Yeah, I saw that post, but I don't know enough to understand if the ardweeny board is required to get the thing to work, or if it can work the chronodot alone. I'm not above drilling a hole in the case if I need to- I have a Dremel and I'm not afraid to use it...

[adafruit_support_bill]

You don't need the ardweeny, just the chrono-dot. The BulbDial clock is designed to accept either the DS1307 or the ChronoDot. You might check the schematics for that to see how they connect it.

[adafruit_support_bill]

Sorry, I was mistaken about the BulbDial. It uses either the internal Arduino clock or the Chronodot.

[mike31416]

This thread describes a way to get better accuracy:

viewtopic.php?f=41&t=12720&start=0

You will need to make code changes however. I have made this change and now have a couple of seconds drift over 2-3 weeks.

Mike

[macegr]

I guess I don't really have an idea of the size of the Ice Tube Clock, I had imagined it was pretty big but if the ChronoDot can't fit inside, I guess not.

Even if the ChronoDot can't fit, you could still find a wide-SOIC to DIP adapter board and make your own little DS3231 board. It doesn't really need any external components besides I2C pullups, you could squeeze the battery somewhere and run wires. That way you should be able to fit everything inside the clock.

The DS3231, if you get one running, will be headache free and far more accurate than any software trimming scheme. Any of the software or analog frequency calibration schemes are flawed as soon as you start having temperature variations. With the DS3231, you could put the clock outside or on a sunny windowsill or next to a HVAC vent and it will still keep accurate time. The temperature compensated crystal works great...for me the DS323x is my most favorite Maxim product and one I actually think is worth the money and hassle of dealing with Maxim.