Week 12: Output devices

This week assignment was to design a board for an output device and experiment with it. Although all of the output devices in Neil's keynote were interesting to experiment with, I decided to make a board for an LCD because in my final project I am using an LCD.

I started to design the board in Eaglecad. For connecting the LCD to the board I was planning to use the flat cable and a IDC 2x5 connector. Therefore on the board I needed a 2x5 pin header that I did not find in eagle libraries. Because of that I decided to modify the AVRISP that had a footprint of 2x3-smd. I found a tutorial on Youtube how to modify a part of library in Eaglecad . I also found two more tutorials from sparkfun and instructable for making library parts in Eaglecad which were useful.

For making the part, the first problem I encountered was that I could not save the parts in the libraries. I searched for what it could be the reason and found out that I did not have the permission to write in my Eagle folder. I went to my eagle folder and gave the permission of read and write to it. The second problem was when I had made the part ready but I was getting an inconsistency error between sch and brd. I could place the part in schematics but when I was going the board view I could not see that. I did not understood why it was happening. Finally I did all the same in another computer and it worked.

Designing the board

I designed the board the same way as former weeks in Eagle cad. Then I exported it as a .png file from Egalecad with the resolution of 500 dpi while monochrome was checked. I opened this file in GIMP, cropped it in the size I wanted and made two files for traces and the interior.

The schematics

The layout

The traces

The interior

Making the board

I made the board like former sessions and then soldered the componets.

Board

Stuffed board

LCD

The LCD that I used for this exercise and its datasheet can be found from Digykey for example. This LCD is has 2 rows and and 16 columns. It has also 16 pins to connect wire to which are numbered at the back of the LCD. For communicating with the LCD connecting to 10 pins (1-6 and 11-14) would be adequate for communicating with the LCD. Pins (7-14) are the data bus. On the software it can be defined if the we are gonna use an 4 bit or 8 bit data bus. In this exercise we are using a 4 bit data bus.

One sample code that I tried was for making custom characters. I learned how to do it when I was watching Jeremy Blum video about LCD. As mentioned above the LCD I was using was 16x2. In each of these spots there are 5x8 pixels that can be turned on or off to make new custom characters.

   
 // include the library code:
#include 

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(5, 4, 3, 2, 1, 0);

byte firstColume[8] ={

    B00000,
    B00000,
    B10000,
    B10000,
    B10000,
    B10000,
    B00000,
    B00000,
};

byte secondColume[8]={

    B00000,
    B00000,
    B11000,
    B11000,
    B11000,
    B11000,
    B00000,
    B00000,
};
byte thirdColume[8]={
    B00000,
    B00000,
    B11100,
    B11100,
    B11100,
    B11100,
    B00000,
    B00000,
};
byte fourthColume[8]={
    B00000,
    B00000,
    B11110,
    B11110,
    B11110,
    B11110,
    B00000,
    B00000,
};
byte fifthColume[8]={
    B00000,
    B00000,
    B11111,
    B11111,
    B11111,
    B11111,
    B00000,
    B00000,  
};


void setup() {
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("Fabacademy 2014");
  
  lcd.createChar(0, firstColume);
  lcd.createChar(1, secondColume);
  lcd.createChar(2, thirdColume);
  lcd.createChar(3, fourthColume);
  lcd.createChar(4, fifthColume);
  
}


void loop() {
  // Moving the cursor to second line
  lcd.setCursor(0,1);
  //clear the second line when it reaches to the end
  lcd.print("                "); //16 spaces 
  for (int i = 0; i < 16; i++)
  {
      for (int j=0; j < 5; j++)
      {
        lcd.setCursor(i,1);
        lcd.write (j);
        delay(80);
      
      }
  
  }
  
}