Lab 3 — Morse Code Lock

For Lab 3, I decided to follow the prompt in the syllabus from last week and make a lock, incorporating everything we’ve learned so far. I decided to use morse code as the lock mechanism — using a button press, you had to type in the morse code for “open”, which is as follows (hyphens are long, dots are short).--- .--. . -.

I used an arduino speaker to mimic the sound of a morse code button, LED lights to signify when the box was locked or open, and a servo to open the box (this step didn’t work quite as well because my servo is extremely weak).

For the morse code, I just used Arduino’s array storage for comparison values (basically, assuming any button press over a second and less than two seconds was “long” and anything under a second was “short”), storing press values up to 10 and then wiping them if the button was inactive for more than 3 seconds.

You can see my (probably overly complex) code here:#include <Servo.h>
Servo servoMotor;
int servoPin = 9;const int PIN = 3;
const int PRESS = HIGH;
const int NOPRESS = LOW;
bool isOpen = false;
unsigned int storageIndex = 0;
int storage[10];
int combinationUpper[10] = { 200, 200, 200, 100, 200, 200, 100, 100, 200, 100 };
void setup() {
 // put your setup code here, to run once:
 Serial.begin(9600);
 servoMotor.attach(servoPin);
 pinMode(3, INPUT);
 pinMode(9, OUTPUT);
 pinMode(10, OUTPUT);
 pinMode(11, OUTPUT);
 pinMode(6, OUTPUT);
}void loop() {
unsigned int pressCount = 0;
unsigned int noPressCount = 0;
 if (digitalRead(PIN) == PRESS) {
   while (digitalRead(PIN) == PRESS) {
     tone(6, 500);
     pressCount += 1;
     delay(5);
   }
 }
 if (digitalRead(PIN) == NOPRESS && pressCount > 0) {
   noTone(6);
   storage[storageIndex] = pressCount;
   Serial.print("index and value: ");
   Serial.println(storageIndex);
   Serial.println(pressCount);
   storageIndex += 1;
   if (check() == 10) {
     isOpen = true;
     servoMotor.write(90);
     Serial.println("open!!!!!!");
     digitalWrite(10, HIGH);
     digitalWrite(11, LOW);
   }
   while (digitalRead(PIN) == NOPRESS) {
     noPressCount +=1;
     if (noPressCount >= 3000) {
       isOpen = false;
       wipe();
       servoMotor.write(0);
       Serial.println("wiping");
       check();
     }
     if (isOpen == false) {
       digitalWrite(10, LOW);
       digitalWrite(11, HIGH);
     }
     delay(5);
   }
 }
}
int check() {
     unsigned int check = 0;
     for(int i = 0; i <= 9; i++) {
     Serial.print(i);
     Serial.print(": ");
     Serial.println(storage[i]);
     if (storage[i] <= combinationUpper[i] && storage[i] > (combinationUpper[i] - 100)) {
         check += 1;
       }
     }
     Serial.print("check: ");
     Serial.println(check);
     return check;
}void wipe() {
 for(int i = 1; i <= 10; i++) {
   storage[i] = 0;
 }
}

This lab turned out fairly well, although working with Arduino code is taking some getting used to — I never know what’s going to end up throwing my timing off. My final circuit is here:

And you can see it in action here (complete with not-so-effective opening mechanism):