Morse codes and Arduino

My son Svante came home Friday and told me that he had been working on Morse codes in science class. We talked a bit on how to translate sentences to Morse code. Yesterday evening I had to construct a translator using my Arduino board, a LED and a LCD display. The program is pretty simple. It processes the message - letter by letter - and shows the current letter in capital and the Morse code on the second line. Moreover, it blinks the Morse code using the LED. You find my program below.

#include <stdio.h>
#include <stdlib.h>
#include <LiquidCrystal.h>

int LED  = 9;
LiquidCrystal lcd(10, 11, 12, 13, 14, 15, 16);
char msg[] = "super seje mig";
char m[16];
char *morse[] = {
  "*-",       // A
  "-***",     // B
  "-*-*",     // C
  "*--",      // D
  "*",        // E
  "**-*",     // F
  "--*",      // G
  "****",     // H
  "**",       // I
  "*---",     // J
  "-*-",      // K
  "*-**",     // L
  "--",       // M
  "-*",       // N
  "---",      // O
  "*--*",     // P
  "--*-",     // Q
  "*-*",      // R
  "***",      // S
  "-",        // T
  "**-",      // U
  "***-",     // V
  "*--",      // W
  "-**-",     // X
  "-*--",     // Y
  "--**"      // Z
};
void setup() {
  lcd.begin(16, 2);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Booting");
  for(int i=0; i<16; i++) {
    lcd.setCursor(i, 1);
    lcd.write('.');
    delay(100);
  }
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("K. Geisshirt");
  lcd.setCursor(0, 1);
  lcd.print("Copyright 2012");
  delay(1000);
  pinMode(LED, OUTPUT);
}

void loop() {
  for(int i=0; i<strlen(msg); i++) {
    for(int j=0; j<strlen(msg); j++) m[j] = msg[j];
    m[strlen(msg)] ='\0';
    if (m[i] != ' ') m[i] = m[i]+('A'-'a');
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(m);
    lcd.setCursor(0, 1);
    if (m[i] != ' ') {
      lcd.print(morse[m[i]-'A']);
      for(int j=0; j<strlen(morse[m[i]-'A']); j++) {
        digitalWrite(LED, HIGH);
        if (morse[m[i]-'A'][j] == '*') {
          delay(500);
        } else {
          delay(1000);
        }
        digitalWrite(LED, LOW);
        delay(250);
      }
    }
    if (m[i] != ' ') {  
      delay(1000);
    } else {
      delay(100);
    }
  }
}

If you haven't tried an Arduino board, it is highly recommended. With an electronic brick and a few components, it is much like LEGO for adults.

Edit: I have added a video.

GNOME 3

GNOME 3 - a review

After the arrivel of GNOME 3 and Unity, we have seen months of discussion on the future of the free desktops. Both GNOME 3 and Unity have been considered as a step backward. Many old-school Linux users believe that these new offerings are worse than the good well-documented desktops like GNOME 2 and XFCE.

Over the years I have used many different desktop environments and window managers. GNOME 2 (both for Debian GNU/Linux and Ubuntu Linux) has served me well. A couple of weeks ago, I decided to try out GNOME 3. And to jump to the conclusion - GNOME 3 is different!

In my test of GNOME 3, I use my four years old Dell XPS 1330M laptop. With an Intel Core2 Duo (2 GHz), 4 GB memory and Intel graphics, it is not a speed devil. But it is a small laptop, and I can carry it around (I'm usually on bike) easily. I have upgraded the battery to a 9-cell battery, and that gives me enough power to work for long period without plugging it to the wall. The operating system is Arch Linux (64 bit).

Is the difference between GNOME 2 (old-school desktop) and GNOME 3 a good thing? Yes, I like it. I like that the panel is so small - yeah, I know it's not a panel. And I the activity concept. I use the same 5 applications (browser, editor, terminal, word processor, and photo manager) so adding them to the activity panel is pretty nice. It took a couple of days to get use to the virtual desktops. In many years I have visualized my virtual desktops horisontal (and used Ctrl-Alt-Left/Right to move between them). Now, they are vertically organized (Ctrl-Alt-Down/Up). One thing I like is that the number of virtual desktops are changed dynamically as I move between them and starting and stopping applications.

The idea that you must use the Alt key together with the top-right menu is new to me. Luckily, a friend showed me after a week that I can power down my laptop as the menu changes when I press Alt. For one week I logged out and powered down. Knowing that the meta keys (Alt, Windows, etc.) is used throughout the GNOME Shell, makes me a bit more productive - or probably closer to my GNOME 2 productivity. I can only recommend that you read the user's manual to GNOME 3 and the GNOME Shell when you start using GNOME 3 for the first time.

One of the most critized parts of GNOME 3 has been that it is not possible to customize the desktop. Strangely, I have not encountered many problems with this. Maybe the default values are just right for me. Of course I have changed a few things, but I have not wished to customized an item and haven't been able to find it.

The network manager has been upgraded, and this is the place where I think it is a downgrade. The VPN dialogs do not allow to import configuration files. Typically your network administrator will send you the configuration in some sort of file (each VPN implementation has it own format). I can manually type in the information, but it was much nicer in previous versions where I could import it.

The default applications in GNOME 3 are fine with me. I have only changed two applications: Firefox as browser, and Emacs as editor. The GNOME Editor (gedit) is not powerful enough for a full time software developer like me (working in 3-4 programming languages at the same time).

GNOME 3 introduces a concept of online accounts. The idea is that you register your accounts on place and all application can use the information. Currently, only Google accounts are supported, but it is really nice that Evolution, Empathy and GNOME Shell calendar take advantage of it. I hope that Twitter, Facebook, LinkedIn and other web services soon will be supported.

For almost three weeks I have been using GNOME 3, and I must say I am impressed. The GNOME developers have really tried to rethink the free software desktop - and they have produced a cool desktop!