Catapult

• Torsion spring loaded arm and cup
• Motor pulls arm back via steel cable
• Clutch for release/engage
  • Potentially use dog clutch

Chassis

• Built on iRobot Create 2

Reloading

• 2 holding containers
• Servo controlled release flaps

Controller: Arduino Uno, Due, or Teensy 3.4

• Connected to RC receiver (Rx) via PPM (single-wire RC-style pulses in serial)
• Connected to iRobot Create 2 via serial (iRobot Create open interface)

Battery: 3S (11.1V nominal) Lipo Pack (capacity to be determined)

Sensors

• Battery-powered wifi web camera (possibly with pan/tilt capability)
• Potentiometer for catapult position feedback

Motors/servos:

• (2x) high-torque RC servos for beanbag loading mechanism
• DC motor with gearbox (window motor?) or stepper motor
• Solenoid for engaging/disengaging clutch

Arduino Uno (C derivative)

Interpret RF signals from COTS controller

Movement:

• Convert RC signals (1.0-2.0us pulses) from joysticks into -255/255 digital
• Send -255/255 as raw motor commands to iRobot Create over serial

“Throw” command:

• Release clutch to throw loaded beanbag
• Winch down motor until at desired position
• Control loading order (load beanbag 2 or beanbag 3)

Windows laptop:

• View wifi webcam