Overview● What We Will Talk About
– Light Sensor Configuration– Electrical physical set-up– Line following changes– Battery– Bumper– Buzzer– Results– Future
●What We Won’t Talk About–Specific tasks
●Most approaches were●similar
Light Sensor Configuration● Three sensors,
angled instead of parallel
● 15cm high, 13.5º spread of sensors
● Allows a larger field of view when detecting whether lights are on or off
Physical Setup of Electrical Components
● Too many uninsulated wires
● Too great a chance of short circuit at LED level
Bender: Milestone 2
Physical Setup of Electrical Components
● Less chance of short circuit
● Easier placement of sensors
● Easier connection of large number of sensors (seven)
● Fun-tac used to hold sensors in housing
Battery Problem
● Four days lost because of intermittent resetting of the NMI board
● Slow-blow fuse partially blown● Code that left values on the stack● “Cooked” battery● All lead to problems that reset the board
Bumper
● Originally mounted too low● Required due to missing mounting bracket● Supported by a loose wooden block
Buzzer● Problems connecting the buzzer
– DDRD must be set (so that Port D pins are appropriately used for output)
– Port D pins 0 and 1 are used for the serial port
– Thanks to the Dogs Of Thunder for supplying the transistor and the know-how.
Code● State based● Required meeting one task before the next could begin● Unable to recover from errors
● Loop {– On Marker
● Enter State● Perform “canned” series of movements● Change state to reflect completion
● }
Failure…?
● Completed one full lap of the track during the first part of evaluation
● In point-based test, failed to complete one lap, leaving us in last place (300 points)
● Uncertain why system suddenly failed– Happened twice in the same place, gives us something to look
into● Lesson:
– Expect it to happen from time to time– Build system robust enough to deal with such errors and
continue
Future Plans
● Analog multiplexer– Many sensors are currently being used– Only one port E pin remaining
● Rewiring– Simplify wiring setup
● Rethink Benders Design– Too much “just make it work” due to time constraints
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