Parts:

The design of the box was fairly simple. I used some past tinkering ideas to bring it all together in less than a week. Note, the items and links are more of just a reference for you – any variant of these items should do the trick.

Total Cost: ~$96

Microcontroller Code:

The code for the microcontroller was relatively straightforward to the program. The only requirements I had were:

1. The default state of the servo needed to be locked.
2. The servo needed to unlock the device when powered & when the proper button was pressed.

Here’s the code:

#include <Servo.h>  // add servo library
#define switchPin 6

Servo myservo;  // create servo object to control a servo
const uint8_t MAX_POSITION = 70;//180;
uint8_t servoPosition = 0;

void setup() {
  // Set the data rate
  Serial.begin(9600);

  // Set switch pins
  pinMode(switchPin, INPUT_PULLUP);

  // Attach the servo on pin 9 to the servo object
  myservo.attach(9);

  // Set the servo to position zero+
  myservo.write(0);
  delay(100);
}

void loop() { 
  if (isSwitchPressed() == true) {
    // If we are already there, don't go farther
    if (servoPosition == MAX_POSITION)
      return;

    Serial.println("Rotating");
    Serial.println((String)"Starting Servo Position: " + servoPosition);
    for (servoPosition = 0; servoPosition < MAX_POSITION; servoPosition += 1) {
      // Rotate the servo
      myservo.write(servoPosition);

      // Give the servo time to work
      delay(15);
    }
    Serial.println((String)"Ending Servo Position: " + servoPosition);
  }
  else {
    // If we are already there, don't go father
    if (servoPosition == 0)
      return;
      
    Serial.println("Resetting");
    Serial.println((String)"Starting Servo Position: " + servoPosition);
    for (servoPosition = MAX_POSITION; servoPosition > 0; servoPosition -= 1) {
      // Rotate servo
      myservo.write(servoPosition);

      // Give the servo time to work
      delay(15);
    }
    Serial.println((String)"Ending Servo Position: " + servoPosition);
  }
}

bool isSwitchPressed() {
  if (digitalRead(switchPin) == 0) {
    return true;
  }
  else {
    return false;
  }
}