I try to use Servo motor to create something fun. I come up with a thief trap idea. When some one come close to your belongings, there will be some alert to threaten them. I use ultrasonic sensor to detect the intruder distance and servo motor to activate a trap.
The structure of the trap is simple. When intruder come near the ultrasonic sensor, the sensor will send some signal to make servo motor activated. The servo motor will trigger the key to drop.
In this lab, I have several struggle point. The first one is when I use servo motor, the number is not reset to 0. This effect make the trap less consistency because of the angle that servo motor is going to hit the key. Second problem is the material. At first, I tried to ring some bell with servo motor. I tried with a couple of materials. Some of them is to light that do not make any noise when wood stick hit it.
reference for ultrasonic code : https://randomnerdtutorials.com/complete-guide-for-ultrasonic-sensor-hc-sr04/