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Topic: stepper driven mechanical clock with RTC (Read 979 times) previous topic - next topic

arduinodale

I looking at the feasibility into designing a mechanical clock driven by a stepper motor with no escapement as I'm after a true sweeping second hand. I would like to be able to correct the time with something like this - Ultra-precise Real Time Clock - v2.1 ( http://www.adafruit.com/products/255 ). I'm wondering what would be the best way to get feedback from the clock works to tell the arduino the time on the works.

Regards

Dale

LarryD

The way you have it in your schematic isn't the same as how you have it wired up!

terryking228

Hi, So this would be a clock with gears for the second-minute-hour relationship and one stepper motor driving second hand??

You might use 3 reflective IR sensors like these: http://goo.gl/05jZ9

If you have the conventional coaxial connection to the 3 hands, you could selectively make them reflective at different distances from the center, have 3 sensors, and be able to detect the 12:00:00 condition.  Drive to that and then assume your stepper won't miss steps to set the time.

At least it would be impressive while setting the time. Kind of like a cheap movie: "Time Passes"....


DISCLAIMER: Mentioned stuff from my own shop...
Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

arduinodale

Hi,

Thanks for the replies, yes it will be driven off one stepper, I might even add an idler gear off the main hour hand gear to detect position. Terry I had a look on your site, I do like the look of the light beam sensor, all I would need to do is mill a slot in the idler gear.

Regards

Dale

terryking228

Dale, if you can get access to the gears "back there" for a transmissive beam you could, use something like this:

http://goo.gl/eBpHx

or pairs of these (first 2 items here: http://goo.gl/SuCwq)

You'd only need a small hole in the gear.


DISCLAIMER: Mentioned stuff from my own shop...
Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

arduinodale

Hi,

Yes I think this is the route I'll take ( transmissive beam ), still in the design stage so I need to finalize my designs

Many thanks

Dale

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