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interfacing a keyboard and lcd screen on arduino

Former Member

Hi there i have a PS2 keyboard and  simple 16X2 LCD screen

 

does anybody have a source code that make the two interface ?

 

i've tried to write one bymyself using the examples in the arduino (the simple test for the keyboard using the keyboard libraray afcourse and the liquid display libraray)

 

here it is

 

/* in this program I will connect lcd to keyboard and print hello world

 

the circuit  :

LCD -

* LCD RS pin to digital pin 12

* LCD Enable pin to digital pin 11

* LCD D4 pin to digital pin 6

* LCD D5 pin to digital pin 5

* LCD D6 pin to digital pin 4

* LCD D7 pin to digital pin 3

* LCD R/W pin to ground

* 10K resistor:

* ends to +5V and ground

* wiper to LCD VO pin (pin 3)

 

Keyboard -

*Data - pin 8

*Clk - pin 2

*/

 

 

//includes

#include <LiquidCrystal.h>   //LCD library

#include <PS2Keyboard.h>       //Keyboard library

 

// initialize the library with the numbers of the interface pins

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

 

//initialize the Keyboard

const  int DataPin = 8;

const   int IRQpin =  18;

 

 

PS2Keyboard keyboard;

 

 

void setup() {

              // set up the LCD's number of columns and rows:

              lcd.begin(16, 2);

             //set up the kyeboard to recieve data

  delay(1000);

  keyboard.begin(DataPin, IRQpin);

  Serial.begin(9600);

   

   

           

              Serial.println("Keyboard Test:");

    

}

 

void loop() {

                       // set the cursor to column 0, line 1

              // (note: line 1 is the second row, since counting begins with 0):

            lcd.setCursor(0, 1);    

             //lcd.setCursor(1,1);

              //reading the keyboard and print it to the screen if necessary

              if (keyboard.available()) {

                             // read the next key

                          char(c) = keyboard.read();

              }

                else {

                               // otherwise, just print all normal characters

                                char c = keyboard.read();

                                Serial.print(c);

                }

               

               

               

}

           

              

 

the problem is that the code is complied and also can be uploaded to the arduibo the problem is...it doesnt do what is  suppose to do which is :

 

 

each button i will press on the keyboard will appear  on the lcd

Parents

  • chen

    I'm picking that it doesn't even display "keyboard test" ?

     

    The code you've copied looks like its writing to a serial LCD, and yours is not (based on the connections in the sketch).

     

    try

    lcd.setCursor(0,0);  // First position (0) and first line (0)

    lcd.print (" Keyboard test ");

     

    instead of Serial.println("Keyboard Test");

     

    and

    lcd.setCursor(0,1);  // First position (0) andsecond line (1)

    lcd.print (c);

     

    instead of Serial.print(c);

     

    if you were to open the Serial monitor at 9600 baud, I'll bet you can see the "Keyboard Test" and then the char you type.

    Trying his first will at least shown if the keyboard is working...

     

     

    Mark

  • in reply to mcb1

    thanks !! that did the trick it works

     

    thank you very much

     

    one more question though sorry for being a nag

     

    it writes the notes over the other ones..if i want to that the letters and stuff i type to come one after the other i need to use a for loop?

     

    and one more question how can I define the functions of special keys as space bar and esc and delete (when i try to type delete it writes delete how can i program it to actually delete?)

Reply
  • in reply to mcb1

    thanks !! that did the trick it works

     

    thank you very much

     

    one more question though sorry for being a nag

     

    it writes the notes over the other ones..if i want to that the letters and stuff i type to come one after the other i need to use a for loop?

     

    and one more question how can I define the functions of special keys as space bar and esc and delete (when i try to type delete it writes delete how can i program it to actually delete?)

Children
  • in reply to Former Member

    Chen

    well done

     

    Your loop always resets the cursor to position 0, and so it will overwrite.

     

    The keys all have ascii codes, although not printable.

    (i've never tried it ...)

    You just need to use an if statement (or a switch case) to choose what to do.

     

    ie when you get a space instead of lcd.print(c) try lcd.print(" ")

    for esc if you wanted it to clear everything you have the command lcd.clear(), BUT remember to reset the cursor position ....

     

    For the deleting, you need to know how many letters you have and write a space over the last one.

    There may be options to change text direction, but try knowing what you have entered/displayed so you can use it later in the program.

     

    You can store the entries into an array, or simply make up a string

     

    Have a go, see where you get stuck, you'll learn more than if someone gives you the finished code.

    The various commands available are at http://arduino.cc/en/Reference/LiquidCrystal?from=Tutorial.LCDLibrary

     

     

    Mark

    PS

    You have the option of marking answers correct or helpful, which I believe are visible to you at the bottom (sorry never seen them, only answered not asked)