Gear Clock using PIC16F676 Microcontroller

I can’t take credit for the design of this one.  I bought the
gear as a clock a few years ago.  It was mounted on a frame
and had one of those cheap clock units running it.  The
gear is designed to be driven by the minute-hand shaft of
the clock mechanism.

The problem was that it kept breaking.  I think the problem
was that the clock mechanism wasn’t strong enough to hold
the weight of the gear.

I bought a stepper motor with four input wires.  A PIC
16F676 microcontroller functions as the timer.  Every
three minutes, four output pins are driven either high
or low for half a second.  These are each connected to
a pair of transistors – one PNP, one NPN to drive the
motor with more current.  The stepper motor rotates 18
degrees each time.

For more detail: Gear Clock using PIC16F676 Microcontroller

Current Project / Post can also be found using:

• 16f676 i2c
• pic 16f676 led clock code