Morse-Code | home
LED Projects | Prop. Clock Version 1 | Prop. Clock Version 2 | Handheld POV | 5x7 Font Editor | VU-Meter | Audio Analyzer | HPDL2416 Display | Binary Watch | 8x8 Scrolling LED Matrix | 7x20 LED Matrix Display | 5x5x4 LED Matrix
Prop. Clock Version 2
This is my second version of a propeller clock.
The one main difference from Bob Blicks version is that this clock does not get its power
from the motors commutator points. It actually gets its power directly from the motor source.
And this clock has 3 Modes, scrolling Text display, analog clock mode and digital clock mode.
I used 10 Blue LED's, 7 for the characters, 3 for the inner LED's when in Analog mode, and 1 Orange LED for the outer ring.
I ended up stumbling upon this nifty little motor assembly, manufactured by Shinano Kenshi Co. Ltd. of Japan.
I had a few of these that I salvaged out of some defective Laser Barcode Readers.
With its slim profile, this should be perfect! The manufacturer was nice enough to label the connections on the main PCB connector, it has a connection for the
source power and ground, and also, an enable pin for the motor. With the enable pin, the clock can remain powered with out the motor spinning! (In case I wanted to do a display on demand feature, where the clock only spins when I want it to display the time.)
I used a bronze collar that I bored out to fit a nylon spacer into it, that way I could insulate the collar from the shaft. Then I soldered a short
piece of wire, to the collar (which spins with the motor shaft), and connected that to the +5 on the PCB, the shaft
of the motor is what's used for the ground connection for the PCB.
I then took a spring loaded DC Motor brush assembly, (which I just happen to have laying around!)
and used that to supply the 5v I needed for the clock circuit.
Surprisingly enough, this setup is quieter than my first clock.
I had bored a hole through the mounting "plaque" I used as the base, and had the motor mounted on the
back side of the base.
In the photo above left, you can see the Hall-Effect sensor I used to change the time setting.
The photo on the right and below left shows the IR pair I am using for the timing input.
I used a PIC16F84A for the MCu.
This is what the clock base looks like, it was actually a mount for a fantasy knife that I bought, but I didn't like the look of the knife on
this particular mount, so I kept it around for another use, such as this.
Download a short avi clip to see the clock in action below...
(Right click on link above and choose save target as...)