Unfortunately the provided code did not work and I had to modify a lot of parts to finally get the display to work. I had to invert the “HIGH” and “LOW” params in all the function calls and change the way the constants are defined in the beginning.

I can’t really explain to you why there is such a difference between my working code and the code provided in the article I based myself on since I’m still a beginner. I might be using a different display and a different version of the IDE. When I’m advanced enough to figure that out I’ll make sure to update the article. If you can explain the reason to me please do so in the comments.

Here’s the updated code, I also created an additional function that plays a little “snake” animation on the display.

//7-segment LED by eliedh.com
const int A = 8;
const int B = 9;
const int C = 2;
const int D = 3;
const int E = 4;
const int F = 5;
const int G = 6;

void clr()
{
  //Clears the LED
  digitalWrite(A, LOW);
  digitalWrite(B, LOW);
  digitalWrite(C, LOW);
  digitalWrite(D, LOW);
  digitalWrite(E, LOW);
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);

}

void drawLoop()
{
  digitalWrite(G, HIGH);
  delay(100); 
  digitalWrite(C, LOW);
  delay(100);
  digitalWrite(A, HIGH);
  delay(100);
  digitalWrite(G, LOW);
  delay(100); 
  digitalWrite(B, HIGH);
  delay(100);
  digitalWrite(A, LOW);
  delay(100);
  digitalWrite(E, HIGH);
  delay(100);
  digitalWrite(B, LOW);
  delay(100);
  digitalWrite(D, HIGH);
  delay(100);
  digitalWrite(E, LOW);
  delay(100);
  digitalWrite(C, HIGH);
  delay(100);
  digitalWrite(D, LOW);
  delay(100);
}

void char_A()
{
  digitalWrite(D, LOW);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void char_B()
{
  //Displays B
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, LOW);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void char_C()
{
  //Displays C
  digitalWrite(D, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(F, LOW);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void char_D()
{
  //Displays D
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, LOW);
  digitalWrite(A, LOW);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void char_E()
{
  //Displays E
  digitalWrite(D, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void char_F()
{
  //Displays F
  digitalWrite(D, LOW);
  digitalWrite(E, LOW);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void char_G()
{
  //Displays C
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, LOW);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void char_H()
{
  //Displays H
  digitalWrite(D, LOW);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, LOW);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void char_I()
{
  //Displays I
  digitalWrite(D, LOW);
  digitalWrite(E, HIGH);
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);
  digitalWrite(A, LOW);
  digitalWrite(B, HIGH);
  digitalWrite(C, LOW);
}

void char_J()
{
  //Displays J
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);
  digitalWrite(A, LOW);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void char_L()
{
  //Displays L
  digitalWrite(D, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(F, LOW);
  digitalWrite(G, HIGH);
  digitalWrite(A, LOW);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void char_R()
{
  //Displays R
  digitalWrite(D, LOW);
  digitalWrite(E, LOW);
  digitalWrite(F, HIGH);
  digitalWrite(G, LOW);
  digitalWrite(A, LOW);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void one()
{
  //Displays 1
  digitalWrite(D, LOW);
  digitalWrite(E, LOW);
  digitalWrite(F, LOW);
  digitalWrite(G, HIGH);
  digitalWrite(A, LOW);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void two()
{
  //Displays 2
  digitalWrite(D, HIGH);
  digitalWrite(E, LOW);
  digitalWrite(F, HIGH);
  digitalWrite(G, LOW);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void three()
{
  //Displays 3
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, LOW);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, LOW);
}

void four()
{
  //Displays 4
  digitalWrite(D, LOW);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, LOW);
  digitalWrite(B, HIGH);
  digitalWrite(C, LOW);
}

void five()
{
  //Displays 5
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(C, LOW);
}

void six()
{
  //Displays 6
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, LOW);
  digitalWrite(C, HIGH);
}

void seven()
{
  //Displays 7
  digitalWrite(D, LOW);
  digitalWrite(E, HIGH);
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, LOW);
}

void eight()
{
  //Displays 8
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void nine()
{
  //Displays 9
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, HIGH);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, LOW);
}

void zero()
{
  //Displays 0
  digitalWrite(D, HIGH);
  digitalWrite(E, HIGH);
  digitalWrite(F, LOW);
  digitalWrite(G, HIGH);
  digitalWrite(A, HIGH);
  digitalWrite(B, HIGH);
  digitalWrite(C, HIGH);
}

void LoopDisplay()
{
  //Start with a small "animation"
  drawLoop();
  //Loop through all Chars and Numbers
  char_A();
  delay(1000);
  char_B();
  delay(1000);
  char_C();
  delay(1000);
  char_D();
  delay(1000);
  char_E();
  delay(1000);
  char_F();
  delay(1000);
  char_G();
  delay(1000);
  char_H();
  delay(1000);
  char_I();
  delay(1000);
  char_J();
  delay(1000);
  char_L();
  delay(1000);
  char_R();
  delay(1000);
  one();
  delay(1000);
  two();
  delay(1000);
  three();
  delay(1000);
  four();
  delay(1000);
  five();
  delay(1000);
  six();
  delay(1000);
  seven();
  delay(1000);
  eight();
  delay(1000);
  nine();
  delay(1000);
  zero();
  delay(1000);
}

void setup()
{
  //Setup our pins
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
  pinMode(E, OUTPUT);
  pinMode(F, OUTPUT);
  pinMode(G, OUTPUT);
  Serial.begin(9600);  //Begin serial communcation

}

void loop()
{
  Serial.println("Starting\n");
  LoopDisplay();

}

In case you’re wondering, I got the Arduino board, the 7-segment display and a lot of other cool components in this dx.com Arduino starter kit. (I’m not sure if this code will only work with 7-segment displays bought from dealextreme).

It is a window with an empty area in it, just put the window around anything you want to measure and it will give you the size of it directly (in Pixels). You can also set the window to take a certain size you need or change its color.

Here’s a Picture of the Digital Ruler running:

To download and run the program you need to agree to its EULA, If the program doesn’t run you probably don’t have the .Net Framework 2.0 (available in most computers running Vista and XP) so download it from here.

DOWNLOAD

Screen shot:

Features:

-Text Input and Output

You can modify Input text in different ways:
1- Directly writing in the text-box.
2- Paste input text by pressing CTRL+V or by going to Edit > Paste Input.
3- By selecting “Clear Input text” in the “After Conversion settings”
4- By selecting “Clear Input” in the Edit Menu.

You can use the Output text in different ways:
1- By selecting “Cut Output” and “Copy Output” in the Edit Menu
2- By selecting “Clear Output” in the Edit Menu.
3- By selecting “Copy Output text” in the “After Conversion settings”

-Settings:

First you must choose the type of translation (Morse to Text or Text to Morse) after that you can change those settings:

A- Morse Code to use:

1- Letters and Numerals (A to Z, 0 to 9) will be used by default during translations; all other letters will be replaced by a character or a word you choose.
This option cannot be deselected
2- You can choose to deselect the usage of Punctuation and Prosigns, if you do this all other letters will be replaced by a character or a word you choose.

B- Character replacement

If the program doesn’t recognize a letter during translation it will replace with a word or a sign of your choice, you can select one of the preset words or letters or enter your personal replacement.

C- After Conversion
After the program finishes converting the text, it can perform any operation chosen at this point, if you select “Copy Morse Code” it will copy the generated translation, if you choose “Clear Input Text” it will clear the input text

-M-Player

M-Player is a little tool that allows you to play the Morse Code, to use it select where it should read from and press play.
Note that once Morse Playing starts, it cannot be stopped. (Will be fixed in an upcoming version)

-Morse Code Converter

Morse Code Converter is a tool that lets you convert any Morse Code to a Morse Code that can be used in the Morse Code Translator.
You can choose the Auto Conversion Mode, in this mode the Converter will try to detect each character and convert it, If this mode doesn’t work, you can choose your settings manually.
The converted code will be pasted in the Input Box of the Morse Code Converter.

-Minimum Requirements:

To run the Morse Code Translator you must have the .Net Framework (Already available in most computers running XP and Vista) so download it if the program doesn’t start.

Support:

Please use the comment section to ask a question about the Morse Code Translator.

Download:

To Use the program you must agree to its EULA.

DOWNLOAD