Project description:
learning system for reading analog clock for children (circles clock)
12 buttons 1-12 + 3 more buttons for 15,30,45 minutes.
Led screen which represent the time digital and also read the time loudly.
While the child push one of the buttons for exemple one, the circles clock pointed on one
Vice versa....
I need something to begin with....
List of parts first...
Thanks
Itzik
Two servo Motors with controller....
For the Buttons, look at the libraries for keypads. A 16 key keypad should be fine.
And a bit of an idea as to how to Keep the two Hands from wrapping around each other...
I wonder if you could take a cheapie alarm clock and drive it with fast pulses to get where you need?
or at least use the 60:1 pointer mechanism....
regards
Allan
The movement of ordinary rotary servos are limited to 180°, not very useful for a clock. But AFAIR there exist sail winch servos, which allow for 3 full turns.
Ready made analog clocks often use a gear box, for driving both hands by one motor. That's not very handy, because it may take a long time to advance the hour hand with 60 ticks per hour. I have such beasts here, which advance every night from 2 to 12, what takes several minutes, then wait for a DCF77 time code, before they finally advance to the current time again. In such cases I'd remove the gear box, and drive both hands by their own motors.
Clock face -
How about painted hands on two perspex disks, edge driven so they don't interfere with each other.
Two steppers to drive the disks independently in either direction.
Opto sensors as an index, so you recalibrate the angular position of the disks each time you turn past the sensor.
The rest is relatively easy...
Large 4 digits LED module
Audio player (WAV/MP3?) module
Push buttons - big, childproof!
Power supply
Case
Its sound interesting , but I think Im not quite understood the idea with two perpex disks...
Can you be more specific with the explanations.?
Thanks
Surprisingly, i can't find any photo examples - they were 'popular' in the 70s/80s...
Imagine three disks.
The rear disk is opaque with the hour digits printed - fixed in place like a 'normal' clock.
In front of that, you have two transparent disks - one with the shorter 'hours' hand painted, and the other with the longer 'minutes 'hand'.
Those two transparent disks are individually driven from their perimeters by motors that make the 'hands' appear to move 'in front' of the numbers.
You can make the drive mechanism into the base or frame - such that it looks like the hands have no mechanism.
The face and hand artwork is totally independent of the clock mechanism.