Hasan Alper Hepguvendik,
Alexander Helal, and Jeremy Gruttner
Department of Mechanical Engineering, University of Ottawa
Objective
CoinBot plays Heads or Tails in a best 2 out of 3 match with a
player. CoinBot will flip the coin using a solenoid attached to
its hand, recognizes the outcome by using phototransistor with
reflective properties of colors, and responds accordingly with
his voice. Tallies and announces the final score of the match.
Circuits
Circuit for Reading the
Coin
It contains a white LED
to supply constant brightness to the phototransistor for getting
more accurate and consistent readings.
The coin which
was flipped by the solenoid slides down in front of the photo
transistor. In our project the coin has two sides that are
painted. Black (tails), white (heads). (White reflects more,
black reflects less) Phototransistor
reads the intensity of light reflected by the side. And lets
current pass according to the intensity of light reflected
towards the phototransistor by coin. Reading varies between 0
and 5 V. (0 is very dim and 5 is very bright light)
Circuit to check for coin on coin flipper
solenoid
It
is just a phototransistor used as a switch. Since, only thing it
needs is absence of light to confirm the presence of coin, it
eliminates the frustration of buttons.
