by jakob.schnurrer -

12 First Steps with Arduino

It’s not knowing that drives you mad. ~ Jenny Valentine

I read this quote somewhere on the internet and thought, this would be a great start to a new blog post, since it describes my struggles to start doing prototypes. I had no idea, where I should start or what I should do. With no clear direction in mind, I just started doing something. Since the start of this semester I have gotten really interested in Arduino. After the Arduino was introduced to us during class, I took one home and I have been wanting to create/ do something with it.

Developing a first Idea

Being a scout for over a decade, I have encountered multiple ways of encoding a message, mainly as riddles though. So the first idea I had was to create a device, that lets you encode a message. And the easiest one I thought of was morse code. I started, by attaching Modulino modules, pre-built circuit components like sensors or displays, to an Arduino. I used a three button module and the “pixel”, a board housing eight LEDs, one at first.

The idea was simple, by pressing the first button, the Arduino would receive a dot. Pressing the last one would send a dash and the middle one would be used to stand a slash, which is used in written morse code to communicate a break between letters, words and sentences. The first part was very simple, I created a sketch, that wrote the received button pushes as symbols into a string. I created this very easy and very fast.

Since I could write messages now, I needed a way to actually send the message and clear the message, so people could send a new one. First I tested if the Arduino would recognise multiple buttons being pressed at the same time, but it doesn’t. So I came up with the idea of incorporating an end signal, in my case, sending four consecutive pauses would result in the message being “send” or for now displayed and cleared.

Next, I wanted to be able to also display the message, at first I tried to attach the pixel Modulino and use its LEDs to display the message. This would make it easy to decipher between dots, dashes and breaks since each sign could be displayed clearly. Sadly, I couldn’t figure out, how to make the LEDs light up in the way I wanted them to. During most of the tests, they wouldn’t turn on at all or all of them would show the same color, with no difference between dot and dash. So I turned to a different solution, the buzzer, a Modulino that makes buzzing sound, with varying frequencies. Using the buzzer to output the message was much easier and I didn’t have any problems implementing it.

Current State

This was a lot of text now, since I forgot to take pictures I could attach here, but to showcase the first prototype, her is a short video showing the functionality of the current model. The video is in german but I think it will help illustrate, what I did and what the prototype does.

What’s next?

Developing this simple concept further I would want to make use of the wifi capabilities that the Arduino board I am using provides. This way a wireless connection between two Arduinos could be used to send and receive message. As an extra the LED Matrix of the Arduino could display the received letters in clear text so the person receiving doesn’t even have to know morse code, to decipher it.

A setup like this could be used in an escape room, in which two teams of kids have to work together, to open the door, but their only way of communication is to use morse code and send it using the two Arduinos. That way they could share information and complete the next riddle.

Instructions

For this first version, you don’t need a lot, for hardware you would need:

  • an Arduino (capable of using Modulinos)
  • the three button Modulino
  • the buzzer Modulino

After attaching the Modulinos tho the Arduino, you would just have to plug it into a computer and upload this sketch:

#include <Modulino.h>

ModulinoButtons buttons;
ModulinoBuzzer buzzer;

int frequency = 1000;
int duration = 1000;

int countB = 0;

bool button_a = false;
bool button_b = false;
bool button_c = false;

String message = String("Saved Message:");

void setup() {
  Serial.begin(9600);
  Modulino.begin();
  buttons.begin();
  buzzer.begin();
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  if (buttons.update()) {

    if (buttons.isPressed(0)) {
      message = String(message + ". ");
      Serial.println(message);
      countB = 0;
    } else if (buttons.isPressed(1)) {
      message = String(message + "/ ");
      Serial.println(message);
      countB++;
    } else if (buttons.isPressed(2)) {
      message = String(message + "- ");
      Serial.println(message);
      countB = 0;
    }
  }

  if (countB >= 4) {
    pushMessage();
    message = String("Saved Message:");
    countB = 0;
    Serial.println("Message cleared!");
  }
}

void pushMessage() {
  for (int i = 0; i < message.length(); i++) {
    if (message[i] == '.') {
      digitalWrite(LED_BUILTIN, HIGH);
      buzzer.tone(frequency, duration);
      delay(150);
      digitalWrite(LED_BUILTIN, LOW);
      buzzer.tone(0, duration);
      delay(250);
    } else if (message[i] == '-') {
      digitalWrite(LED_BUILTIN, HIGH);
      buzzer.tone(frequency, duration);
      delay(500);
      digitalWrite(LED_BUILTIN, LOW);
      buzzer.tone(0, duration);
      delay(250);
    } else if (message[i] == '/') {
      delay(1000);
    }
  }
}

Lastly, I wanted to share some takeaways from my first “prototype”. Just starting to do something, with no clear goal in mind at first really sparked my motivation, to develop other little projects using the Arduino. Furthermore, I made small “prototypes” of code, that I test before incorporating them into the real thing. Aiming to understand how something works first, before using it. Lastly, I really need to take more pictures, so future blogposts are more interesting. ;D