H ow It W o r k s We’ll attach the toy missile launcher and the ultrasonic sensor to a servo arm (see Figure 20-1) so that the servo sweeps the gun and sensor back and forth across 180 degrees, giving the ultrasonic sensor a wide range of detection. When an enemy is detected, the Arduino triggers the sentry gun and discharges the missiles. For more on the ultrasonic sensor, see Project 18. Figure 20-1: Attaching the toy gun and ultrasonic sensor to the servo arm gives them a wide range of detection and motion.
The key component for this project is the WLToys RC V959 missile launcher, also known as the Walkera Part RC V959-19 missile bullet launcher, intended for radio-controlled helicopters (Figure 20-2). Figure 20-2: The Walkera Part RC V959-19 missile bullet launcher
This cool part is really cheap (around $6 –10) and is widely available online. Inside this launcher is a mini servo that revolves to set off the missiles. The wires that control this servo are white (GND)
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