Download Automatic Whiteboard Eraser Interfaced Using Assembly Language

holding is 8 bits or one byte. Status port uses only 5 bits of data. The bits used
by the status ports are the five most significant bits of an 8-bit register and the
excess bits would be of no significant value and are only treated as padded bits.
(Stewart, Z., 1994)
DC Motors and SPDT Relays
In a study entitled “DC Motor reversing with relay”, tells about the control
functions of relays which are the forward, stop, and reverse actions.
According to this study, the motor should not be switched from one
direction to another unless it is stopped or set to a rest before. Putting a motor
straight into into the opposite direction would be quite dangerous because when
running a motor, it develops a back emf voltage which could add to the current
flow in the opposite direction and probably cause arcing of the relay contacts.
When the forward button is pressed and released, the motor will run
continuously in one direction. The Stop button must be used before pressing the
reverse button. The Reverse button will cause the motor to run continuously in
the opposite direction, or until the stop button is used.
(Collinson, A., 1995)
The motor reversing circuit for operating a bi-directional motor includes
the standard H-bridge relay circuit which includes a first and a second relay. The
first relay is capable of operatively engaging a first contact at a first time period
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