Hi All
This is my firs post .
I'm trying connect Adruino mega and lcd display using RX
Is this connection ok ?? on my lcd is 16 pins and on serial lcd is 14 ( is that ok ?? )
How I can display something ?? I have only blue screen 
This is my firs post .
You really should read the sticky thread near the top of the forum: "How to use this forum".
What we really need is a link to some more information about the serial interface board that you are using.
I found some information about the chip at this website: --> http://www.pichips.co.uk/index.php/P017_LCD_Chip
I found a datasheet here: --> www.byvac.com/downloads/datasheets/P017%20DataSheet.pdf
These two sites seem to describe the IC itself but not the interface board. There is a circuit for a PC board on the data sheet but I am not sure it matches the one that you are using.
I'm trying connect Adruino mega and lcd display using RX
You are going to have to connect the Rx pin of your interface board to one of the Tx pins of your Mega and then come up with a sketch to send data to that Tx pin.
Is this connection ok ?? on my lcd is 16 pins and on serial lcd is 14 ( is that ok ?? )
The serial board appears to have 18 pins, not 14. The extra two pins are used if you have a tri-color backlight and can be ignored in your case. From your pictures I cannot tell if your two boards are connected properly. Typically the small interface board would be mounted behind the larger display board, not 'alongside' or 'above' it as you have done.
Don
I tried this code to display , and nothing only ( blue screen )
// Arduino and LCD setup
void setup()
{
Serial.begin(19200); // era beginSerial
// LCD setup commands: uncomment the ones you want to use
// Note: These codes (i.e. the ones following 254) may have to be changed for
// different manufacturer's displays
// Turn Auto scroll ON
// Serial.write(254);
// Serial.write(81);
//
// Turn Auto scroll OFF
// Serial.write(254);
// Serial.write(82);
// Turn ON AUTO line wrap
// Serial.write(254);
// Serial.write(67);
// Turn OFF AUTO line wrap
// Serial.write(254);
// Serial.write(68);
// Turn OFF the block cursor
// Note that setting both block and underline
// cursors may give unpredictable results.
Serial.write(254);
Serial.write(84);
// Turn ON the block cursor
// Serial.write(254);
// Serial.write(83);
// Turn ON the underline cursor
// Serial.write(254);
// Serial.write(74);
// Turn OFF the underline cursor
// Serial.write(254);
// Serial.write(75);
}
// MAIN CODE
void loop()
{
//backlightOn(0); // turn the backlight on all the time
clearLCD();
Serial.write(" Hello"); // print text to the current cursor position
newLine(); // start a new line
Serial.write("Arduino");
delay(1000);
}
// LCD FUNCTIONS-- keep the ones you need.
// clear the LCD
void clearLCD(){
Serial.write(12);
}
// start a new line
void newLine() {
Serial.write(10);
}
// move the cursor to the home position
void cursorHome(){
Serial.write(254);
Serial.write(72);
}
// move the cursor to a specific place
// e.g.: cursorSet(3,2) sets the cursor to x = 3 and y = 2
void cursorSet(int xpos, int ypos){
Serial.write(254);
Serial.write(71);
Serial.write(xpos); //Column position
Serial.write(ypos); //Row position
}
// backspace and erase previous character
void backSpace() {
Serial.write(8);
}
// move cursor left
void cursorLeft(){
Serial.write(254);
Serial.write(76);
}
// move cursor right
void cursorRight(){
Serial.write(254);
Serial.write(77);
}
// set LCD contrast
void setContrast(int contrast){
Serial.write(254);
Serial.write(80);
Serial.write(contrast);
}
// turn on backlight
void backlightOn(int minutes){
Serial.write(254);
Serial.write(66);
Serial.write(minutes); // use 0 minutes to turn the backlight on indefinitely
}
// turn off backlight
void backlightOff(){
Serial.write(254);
Serial.write(70);
}
Serial.begin(19200); // era beginSerial
According to the data sheet the default baud rate is 9600.
I would suggest starting with a sketch that writes something like "Hello Arduino" to the display once in setup() with nothing in loop().
Also - using code tags not only makes your code more readable it eliminates problems like the smiley face in your backSpace function.
Don