TVout.h error: invalid conversion from 'char' ....

Forum 2005-2010 (read only) Software Syntax & Programs
1

Hi guys, good evening :slight_smile:

i was just trying to create some kind of typewriter effect with TVout.h

but i get this error when compiling: error: invalid conversion from 'char' to 'char*'

i guess this is some trouble with the library cause with serial.print i got it working just fine.

is there a work around for this?

#include <TVout.h>

TVout TV;
int moveVert=0;
int moveHorz=0;
char myString[]={"I was wondering why this is so complicated"};


void setup()  {
  TV.start_render(_PAL);      
  Serial.begin(9600);
}

void loop() {
 
 moveVert=0; 
 moveHorz=0;
 TV.clear_screen();
   
//working:
for (unsigned int x = 0; x < strlen(myString); x++) {
          Serial.print(myString[x]);
          delay(random(200));}
          Serial.println(" ");
   
// gives error:
for (unsigned int x = 0; x < strlen(myString); x++){
     TV.print_str(moveHorz,moveVert,myString[x]);      
     moveHorz=moveHorz+5;
     if (moveHorz >= 100) {moveVert=8;moveHorz=0;} 
   delay(random(200));
   }

     
}
2

The TV.print_str function expects the 3rd argument to be a string, not a single character. You are calling the function with a single character, myString[x], not a string, myString.

3

found a solution to my problem, now discover an empty space in the string and do moveHorz-1 or something

#include <TVout.h>

TVout TV;
unsigned char x,y;
int moveVert=0;
int moveHorz=0;
int endLine=118;
int temp=0;
char text;
char myString[]={"I was wondering why this is so complicated I was wondering why this is so complicated I was wondering why this is so complicated"};


void setup()  {
  pinMode(13, OUTPUT);     
  digitalWrite(13, HIGH);   
  x=0;
  y=0;
  TV.start_render(_PAL);      
  //Serial.begin(9600);
}

void loop() {
 
 moveVert=0; 
 moveHorz=0;
 TV.clear_screen();
            TV.select_font(_5X7);
for (int i = 0; i < 130; i++){


     char temp_str[130];
     strncpy(temp_str,&(myString[i]),130);
     temp_str[1] = '\0'; 
          TV.print_str(moveHorz,moveVert,temp_str);
     moveHorz=moveHorz+5;
     if (moveHorz >= endLine) {moveVert=moveVert+8;moveHorz=0;} 
   delay(random(200));

   }

     
}
4

print_char(x,y,char) would be better here. Something like this would accomplish your goal:

for( int i = 0; myString[i] != '/0'; i++) {
  TV.print_char(moeveHorz,moveVert,myString[i]);
  moveHorz += 6;  //5x7 font actually needs 6 pixels
  if (moveHorz >= 100) {
    moveVert += 8;
    moveHorz = 0;
  }
  delay(random(200));
}

I didn't compile this so there may be an error, but it should work.

5

moveHorz += 6; //5x7 font actually needs 6 pixels

yes i know, but i liked it when the letters merge..

thanx for this code, i'll try this first thing in the morning!