Wiero Screen Problem.

hi all,

i have strange problem 20x4 lcd screen when uploading arduino. when add following lines of code , upload them sends screen crazy random japanese type characters though compiles fine.

code: [select]

if (movesteps < 0){
 lcd.print ("   left  ");
}

if (movesteps > 0){
 lcd.print ("   right  ");
}


if remove above lines of code arduino project works perfectly. above code in main loop body of code show below.


does have idea's i'm mystified.

code: [select]

//include button library
#include <button.h>

// include library code:
#include <liquidcrystal.h>

// initialize library numbers of interface pins
liquidcrystal lcd(12, 11, 5, 4, 3, 2);

#include <pololuwheelencoders.h>
pololuwheelencoders encoder;
char val1, val2;
char s;
 
 int = 0;
 
button button_left = button(6,pullup);
//button button_ent = button (7, pullup);
button button_right = button(7,pullup);


int buttonloop;

unsigned long previousmillis;


void setup()
{
 lcd.begin(20, 4);
 pinmode(8, output);
 pinmode(9, output);
         digitalwrite(8, low);
         digitalwrite(9, low);
         
         pinmode(13,output);
         digitalwrite(13,low);
         //initialize encoder pins 10,13  
         encoder.init(10,13,255,255);
         
 serial.begin(9600);

  lcd.setcursor(0,0);
  lcd.print("********************");
    lcd.setcursor(0,1);
  lcd.print("*     asrtosky     *");
    lcd.setcursor(0,2);
  lcd.print("*    dome runner   *");
    lcd.setcursor(0,3);
  lcd.print("********************");
  delay (4000);
  lcd.setcursor(0,0);
  lcd.print("                    ");
  lcd.setcursor(0,1);
  lcd.print("                    ");
  lcd.setcursor(0,2);
  lcd.print("                    ");
  lcd.setcursor(0,3);
  lcd.print("                    ");
  lcd.setcursor(0,0);
  lcd.print("astrosky domerunner");
  lcd.setcursor(0,1);
  lcd.print("====================");
  lcd.setcursor(6,3);
  lcd.print("az: ");
  //lcd.setcursor(11,3);
  //lcd.print(" deg");
}

const int max_len = 4; // max digits in number plus decimal point
char  strvalue[max_len + 1]; // add 1 terminating null

int index = 0;
int value1;
int value2;
int diffvall;
int movesteps;

void loop()
{

//serial.print("current millis : ");
//serial.println(millis());
lcd.setcursor(10,3);
lcd.print(value1);
   getaz();
   value1 = value2;
  lcd.setcursor(10,3);
  lcd.print(value1);
   buttonpress();
   llegirpos();

 
if (millis() - previousmillis > 15000){

 previousmillis = millis();
getvalue2();
lcd.setcursor(15,2);
lcd.print("   ");
diffvall = (value2 - value1);
lcd.setcursor(15,2);
lcd.print(diffvall);
movesteps = (diffvall * 10);
lcd.setcursor(0,0);
lcd.println(movesteps);

if (movesteps < 0){
 lcd.print ("   left  ");
}

if (movesteps > 0){
 lcd.print ("   right  ");
}

         
        }
     }
 
 
void getaz(){
 if( serial.available())
 {
   char ch = serial.read();
   if(index < max_len && ch != 13) // 13 ascii value of carriage return
   {
     strvalue[index++] = ch; // add ascii character string;
   }
   else
   {
     // here when buffer full or on first non digit
     strvalue[index] = '\0';        // terminate string 0
 
     index = 0;      // reset index next string
       lcd.setcursor(10,3);
     //serial.println(strvalue);
       //lcd.print(value);
   }  
 }
}


void getvalue2(){
           value2 = atoi(strvalue);  // use atof convert string float
           lcd.setcursor(15,3);
           lcd.print(value2);
           
                         previousmillis = millis();
                         //serial.print("previous millis : ");
                         //serial.print(previousmillis);
                         //serial.println();
                }




void buttonpress() {
 
   while(button_left.ispressed()) {    
             digitalwrite(8, high);
             digitalwrite(9, high);
             lcd.setcursor(1,3);
             lcd.print("<--- ");            
}

digitalwrite(8, low);
             lcd.setcursor(1,3);
             lcd.print("     ");


   while(button_right.ispressed()) {    
             digitalwrite(8, high);
             digitalwrite(9, low);
             lcd.setcursor(15,3);
             lcd.print("---> ");              
}

digitalwrite(8, low);
              lcd.setcursor(15,3);
             lcd.print("     ");
}

//capture encoder counts.
void llegirpos() {

 lcd.setcursor(1,2);
 lcd.print("encoder: ");
 lcd.print( encoder.getcountsm1(), dec );
 lcd.print ("    ");  
}




ribuck,
     the top part of code not source of problem. it's somewhere deep dark down inside code. i'll try , see.

this code works fine test top part of post.

code: [select]


#include <liquidcrystal.h>

liquidcrystal lcd(12, 11, 10, 5, 4, 3, 2);

int movesteps = -1;

void setup() {
 lcd.begin(16,2);
}

void loop() {
 
 if (movesteps < 0){
   lcd.print ("   left  ");
 }

 if (movesteps > 0){
   lcd.print ("   right  ");
 }
 lcd.home();
}

:-?

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