Bidirectional Stepper Motor for Altitude Indication

The device is based on ATtiny13 microcontroller which has a mechanical pointer feature that can provide an indication of altitude for the altimeter of a skydiver.

The current-pulse rotary operated watch hand movement is the basis of the concept involved in this design where both clockwise and counterclockwise operations are enabled. To show the altitude on the way up and down, the pointer mechanism moves in both directions.

A rotating part or rotor is contained in all motors as well as a stationary part or stator. In the stator, the current is driven via s et of copper coils or the phase windings in a way where the speed and direction of the rotor is controlled. For each change of current polarity through its phase windings, a fixed fraction of a full rotation is rotated by the rotor of a stepper motor. The particular sequence of current polarity change though each of the windings determines the direction of rotation.

The ATtiny13 manipulates the stepper motor while the stepper motor driver enables the high current pulses that drive the motor. The change of motor direction can be enabled by a push button switch.

Rest of the project