By Vivek Manoharan TAs: William Dubel and Steven Pickles Ball Man – Sensor Oral By Vivek Manoharan TAs: William Dubel and Steven Pickles

Bump Switch Basic use for an ENTER KEY Helps with initializing Ball Man under different conditions LCD feedback initiates use of ENTER KEY

Photocell Resistor Indicates lighting conditions Helpful for differentiating between need for white balance and not

Ultrasound Sensors – SRF-04 Once one sensor is able to ping the tennis ball, respective DC motor will “slow down” to allow robot to turn Then, when ping rates are equal, DC motors will run at same speed straight ahead Experiments

Distance Accuracy Sample table, one SRF-04 Used maximum pre-scaling (1024) 148us = 1in 2 3.0900” 3.0” 3 5.1150” 5.0” 4 10.1928” 10.0” 5 15.3250” 15.0” 6 21.0547” 20.0”

Difference Tests Dual SRF-04 setup Measured offset needed for BallMan to understand “equal” distances 5 0.375” 6 0.563” 7 0.438” 8 9 10 0.625”

CMU Camera Detect contrast level of tennis ball on tennis court Green – Pickup tennis ball Bright Red – Home Base Test range of contrast detection

White Balance Indoors White Balance off

White Balance Indoors White balance on

Conclusion Further tests for CMU need to be run outdoors White balance is crucial for contrasts Ultrasound ranges are not as far as claimed (distances become iffy after 90”)