// include the library code:
 #include <LiquidCrystal.h>

 const int numRows = 2;
 const int numCols = 16;

 const int lcdBackLightPin = 12;
 const int upButtonPin = 6;
 const int downButtonPin = 5;
 const int setButtonPin = 4;
 const int resetButtonPin = 3;

 char* mainMenu[]={"start", "delay", "test"};
 int mainMenuIndex = 0;
 int mainMenuNextItem = 1;
 int mainMenuItemNum = 3;
 boolean menuUpdate = false;

 // initialize the library with the numbers of the interface pins
 LiquidCrystal lcd(13, 11, 10, 9, 8, 7);

 void setup() {
 // set up the LCD's number of rows and columns:
 lcd.begin(numRows, numCols);
 lcd.clear();
 lcd.setCursor(0, 0);
 lcd.print(">");
 lcd.setCursor(2, 0);
 lcd.print(mainMenu[mainMenuIndex]);
 lcd.setCursor(2, 1);
 lcd.print(mainMenu[mainMenuNextItem]);
 digitalWrite(lcdBackLightPin, HIGH);

 pinMode(lcdBackLightPin, OUTPUT);
 pinMode(upButtonPin, INPUT);
 pinMode(downButtonPin, INPUT);
 pinMode(setButtonPin, INPUT);
 pinMode(resetButtonPin, INPUT);

 }

 void loop() {
 if(digitalRead(upButtonPin))
 {
 mainMenuIndex++;
 if(mainMenuIndex >= mainMenuItemNum)
 {
 mainMenuIndex = 0;
 }  
 mainMenuNextItem++;
 if(mainMenuNextItem >= mainMenuItemNum)
 {
 mainMenuNextItem = 0;
 }
 menuUpdate = true;
 }
 else if(digitalRead(downButtonPin))
 {
 mainMenuIndex--;
 if(mainMenuIndex < 0)
 {
 mainMenuIndex = mainMenuItemNum - 1;
 }  
 mainMenuNextItem--;
 if(mainMenuNextItem < 0)
 {
 mainMenuNextItem = mainMenuItemNum - 1;
 }
 menuUpdate = true;
 }

 if(menuUpdate)
 {   
 lcd.clear();
 lcd.setCursor(0, 0);
 lcd.print(">");
 lcd.setCursor(2, 0);
 lcd.print(mainMenu[mainMenuIndex]);
 lcd.print(" <");
 lcd.setCursor(2, 1);
 lcd.print(mainMenu[mainMenuNextItem]);
 menuUpdate = false;
 delay(300);
 }

 }

You can download the file from here: xISTIxHSPC

Buttons assembled

As you can see, I put every button connector two a new column. This way it was easy to wire them and I needed to make cuts only between the connector pins. I also changed the code of the controller:

// include the library code:
 #include <LiquidCrystal.h>

 const int numRows = 2;
 const int numCols = 16;

 const int lcdBackLightPin = 12;
 const int upButtonPin = 6;
 const int downButtonPin = 5;
 const int setButtonPin = 4;
 const int resetButtonPin = 3;

 // initialize the library with the numbers of the interface pins
 LiquidCrystal lcd(13, 11, 10, 9, 8, 7);

 void setup() {
 // set up the LCD's number of rows and columns:
 lcd.begin(numRows, numCols);
 lcd.clear();
 lcd.setCursor(5, 1);
 lcd.print("XistiX");
 digitalWrite(lcdBackLightPin, HIGH);

 pinMode(lcdBackLightPin, OUTPUT);
 pinMode(upButtonPin, INPUT);
 pinMode(downButtonPin, INPUT);
 pinMode(setButtonPin, INPUT);
 pinMode(resetButtonPin, INPUT);
 }

 void loop() {
 if(digitalRead(upButtonPin))
 {
 lcd.setCursor(0, 0);
 lcd.print("UP Button");
 }
 else if(digitalRead(downButtonPin))
 {
 lcd.setCursor(0, 0);
 lcd.print("DOWN Button");
 }
 else if(digitalRead(setButtonPin))
 {
 lcd.setCursor(0, 0);
 lcd.print("SET Button");
 }
 else if(digitalRead(resetButtonPin)

)

 {

 lcd.setCursor(0, 0);

 lcd.print("RESET Button");

 }

 else

 {

 lcd.setCursor(0, 0);

 lcd.print("            ");

 }

 }

It prints to the screen which button is pressed. When you check the source you will notice that buttons actually has a priority order and you can’t press two more than one button at the same time. I used an if else if structure. I will change this later. It is simply so because it was the easiest to test the buttons and update the screen.

You can download the code as a file from here: xISTIx_Buttons

Push button circuit

I have put a two pin connector to a stripe and made a cut between the pins. then I connected one pin (the upper one in the picture) via a 10 kohm resistor to the ground. The same pin is also connected to pin 6 of the arduino.  The other pin is connected to 5v via a 500 ohm resistor. The push button shorts the two pins.

I have modified the LCD test program a bit. Now the LCD background light is on when the push button is pressed. It is just for testing purposes. Later I will change this.

Here is the code: HelloWorldLCDButton

LCD circuit ready

Hello World!

And here is the final design:

Final LCD circuit design

I also promised to upload the LCD test program:

// include the library code:
 #include <LiquidCrystal.h>

 const int numRows = 2;
 const int numCols = 16;

 const int lcdBackLightPin = 12;

 // initialize the library with the numbers of the interface pins
 LiquidCrystal lcd(13, 11, 10, 9, 8, 7);

 void setup() {
 // set up the LCD's number of rows and columns:
 lcd.begin(numRows, numCols);
 lcd.clear();
 lcd.setCursor(2, 0);
 lcd.print("Hello World!");

 pinMode(lcdBackLightPin, OUTPUT);
 }

 void loop() {
 digitalWrite(lcdBackLightPin, HIGH);
 lcd.setCursor(5, 1);
 lcd.print("xISTIx");
 delay(500);
 digitalWrite(lcdBackLightPin, LOW);
 lcd.setCursor(5, 1);
 lcd.print("XistiX");
 delay(500);
 }

Source file is here: xISTIx_Hello_LCD

My source file is based on this example: http://arduino.cc/en/Tutorial/LiquidCrystal

I just simplified the loop and changed the pin numbers according to my circuit. I also added the control for the LCD back light on pin 12.

Finally a comment for Linux 64 bit users. If you use the arduino package I have suggested earlier, you might face some compilation problem. It is because the LCD library is old in that package. I simply downloaded the arduino017 32 bit Linux software from the official arduino site and copied the LCD library from there. It works fine.

I took some pictures, but I do not have the possibility to upload them right now. They are on my phone and I do not have the USB cable with me. I know, I know it has bluetooth connection but after 5 minutes searching for the damn bluetooth activation on my WinXP office laptop I gave up. So pictures will come in the next post. I will also post the source code for the LCD test.

http://blog.makezine.com/archive/2009/07/arduino_on_64-bit_linux.html

Cooooool! It works fine with my Seeeduino which is basically an Arduino Diecimila. Unfortunately it does not support my Arduino Duemilanove boards. The ATmega328 chips are not supported by the avrdude config. If someone knows how to do that I would be glad to hear it.

Modified LCD circuit

I have changed the connection of the contrast potentiometer. Now it is between the ground and 5V. The R/W pin of the LCD is now connected to the ground and not controlled by the Arduino. This way we can save one pin. I use the saved pin 12 to control the LCD back light.

Here is the current state of the wiring. It is not ready yet. I use a 10 pin socket where I will connect the LCD with a ribbon cable. The connection of the socket is almost ready. Only the contrast line is missing from the potentiometer. I will add two pins for connecting the back light of the LCD with a jumper wire. That is also missing.

Wiring the LCD socket

Soldering

connectors

My local shop did not have connectors with 8 legs, so I used two 4 legs.

Here is the Seeeduino with its extra connector:

Seeeduino with extra connector

As you can see now I have duplicate connector for the upper digital I/O pins (lower right in the picture). The upper connector is the new one and it is at standard place. After soldering I inserted pins to the connectors in order to find the right place on the stripboard where I soldered them. I tried to place it where the USB and power connectors of the Seeeduino are at the border of the stripboard. So when I will build the thing to a box I can access them directly from outside.

soldered pins

Now I can simply plug my Seeeduino to the board:

Seeeduino plugged to the shield

Finally I marked the places on the stripboard where I have to make cuts. I used a permanent marker:

Cuts noted

After posting this I just found there is a little mistake. I marked a line for cut which is not necessary. It is your homework to find it

Next I will go on with the LCD circuit. I will use  10 and 2 pin sockets and ribbon cable to connect the LCD.