LCD4884 and serial communication.

Other Hardware Displays
1

I'm newbie in arduino and my first project I'm alredy stuck, so my question is:

How can I display the letters on my display when I use serial com.
I want to display the letters that I type in the serial monitor to show on my display.
I already managed to display the numeric code (100 = d (ascii)) but i want to display the “d” and not the corresponding number.

see the code I've inserted with this post.

Thanks

#include "LCD4884.h"

int val = 0;
char string[10];

void setup() {
  lcd.LCD_init();
  lcd.LCD_clear();
  lcd.backlight(OFF);
  Serial.begin(9600);
}

void loop () {
    while (Serial.available() == 0);
    val = Serial.read();
    Serial.println(val);
    itoa(val, string, 10);
    
    lcd.LCD_write_string(0, 0, string, MENU_NORMAL);

  delay(100); 
}
2

U8g has such an example:
http://code.google.com/p/u8glib/source/browse/sys/arduino/Console/Console.pde

I think u8g will also support your PCD8544 based display. Please check Google Code Archive - Long-term storage for Google Code Project Hosting..

Oliver

3

@olikraus,

I've looked at it but it wasn't made for my lcd (LCD4884).
And it's way to difficult to adjust it for me (newbie).
The only thing I need a answer to how to convert it to a asccii character (so if the arduino received 65 that it display a “a”)
I can make a large switch case loop but I think that there is already a function for that.

4

oh, i understand. I am not an expert on println, but maybe "println((char)val)" helps.

Oliver

5

@Oliver,

Thanks for the reply.
just one step closer to the sollution.
serial monitor mirrors now the good charater but how do I get this to get it works with the lcd?
See the code

#include "LCD4884.h"

int val = 0;
char string[10];
char teststring;

void setup() {
  lcd.LCD_init();
  lcd.LCD_clear();
  lcd.backlight(OFF);
  Serial.begin(9600);
}

void loop () {
    while (Serial.available() == 0);
    val = Serial.read();
    Serial.println((char)val);
    itoa(val, string, 10);
    
    lcd.LCD_write_string(0, 0, string, MENU_NORMAL);
  delay(100); 
}
6

Know one knows the answer to it??

It's just a simple conversion problem (it's just that I don't have enough knowledge of 'c')

The problem is when I type a “d” in the “serial monitor” I get return a “d” but in the diplay I get a “100”
How do I convert the ascii to a letter??

7

instead of

itoa(val, string, 10);

use

string[0] = val;
string[1] = '\0';

Oliver

8

@Oliver,

YES!!!
finaly i"m trying this for about 6 hours to get it work.
Thanks for the solution.

Greet Dave

9

Hi guys,

So I am very new to Arduino and a beginner programmer at best. That said, I am having a similar problem nend in the original post.

My setup:
-Arduino Mega 2560
-LCD 4884
-I/O Expansion shield, for Serial-RS485 communication
-Displacement Laser, communicates of RS485
-SD Card Logger Shield

What I am trying to do:

-Send a command over RS485 to the Displacement Laser asking for a measurement, this is working already. Nine (9) characters and a carriage return.
Should (and does) look like this: %01#RMD**\r

-Receive the measurement (a character string) from the Displacement Laser, again over RS485, I am not sure if this is working yet. Seventeen (17) characters and a carriage return.
Should look something like this: %01$RMD-0142901**

-Display the measurement optimally as just a number and not the character string (I am willing to take baby steps) onto the LCD 4884.
On the screen it should look something like: -14.2901 mm or %01$RMD-0142901** would be acceptable
So far all the screen displays is: ~'
I know how to display text and a regular variable, but apparently its not the same as a serially read variable

-Write/append each new measurement value to a file on the SD card/Logger Shield. Have not yet gotten this far.

My Code (partly self written, partly from examples far-and-wide on the Internet, partly from this forum post (nend and olikraus), I am ignoring the SD card for the meantime:

int EN = 20; //RS485 TX/RX enable pin
int x = 0;
char string[10];
char inputStr = 0;

//Included files for LCD4884
#include "LCD4884.h"


void setup()
{
  pinMode(EN, OUTPUT);
  Serial1.begin(9600);
  lcd.LCD_init(); // creates instance of LCD
  lcd.LCD_clear(); // blanks the display
  pinMode(13, OUTPUT);
  digitalWrite(13, HIGH);
}

void loop()
{
  
    // Enable Data Transfer
    digitalWrite(EN, HIGH);
    
    delay(16);
  
    // Ask for Displacement over RS485 (Serial1)
    Serial1.print("%01#RMD**\r");
    
    delay(12);
    
    // Enable Data Recieve
    digitalWrite(EN, LOW);
    
    delay(16);
    
    // Recieve Value over RS485 (Serial)
    inputStr = Serial1.read();
    
    // Convert Serial1 Value
    string[0] = inputStr;
    string[1] = '\0';

    delay(16);
    
    // Display Serial1 Value on LCD4884
    lcd.LCD_write_string(0,1,string,MENU_NORMAL);
    
    delay(16);
    


}

Help is much appreciated!

-Glenn

10

I think you're only reading one character.

Try:
char mystring[25];
int cnt = 0;

while(Serial.available())
{
mystring[cnt++] = Serial.read(); // receive a byte as character
};

strncpy(string, mystring, cnt);
lcd.LCD_write_string(0,1,string,MENU_NORMAL);