Cricket Ball Line and Length TrackerChris Chester

Corridor of Uncertainty

corridor of uncertainty: PitchVision (2011)

Just outside the offstump

Pitched 3/4 of the way down the pitch

Hard to for a batsman to play

1st Design : Using Pressure Sensor Pad

Issues:• Bulky – would alter the trajectory of the ball• Costly – Pads cost more than $40 each

The ball causes the distance to decrease

Therefore the

capacitance will increase

2nd Design : Using Capacitive Pad

d

d

Calculating Capacitance Microcontroller

used to detect capacitance

Uses RC time constant

• Set up internal clock to count ticks

Internal

Detecting Changing Capacitance Calibrate the Pad Look for Change in

amount of ticks Activate feedback Recalibrate

50

100 𝜇𝑠

300

Observations and Future Considerations Effective Cheap Thin Multiple Uses

• Better interface to the bowler

• Remove alligator clips

Conclusions Pressure Mat had several issues Capacitive Sheet was a cheap, thin

solution. Utilised the Capacitive sensing function

of the microcontrollers Offers several different alternatives

Extra Info PIC16F1827 by Microchip Speed = 250kHz Cost is about $7 W/O LEDs