[SOVLED] how can I pass a variable to function when using TimedAction？

Projects Programming
1

I use TimedAction do multi-threading,one thread controls first line, another controls second.
In example ，no variable was passed into function，but I have following code, need pass variables to both functions. how can I do ?

/********************************/
// first static line,second scroll line

#include <TimedAction.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

/**********************************************************/
LiquidCrystal_I2C lcd(0x3F, 16, 2); // set the LCD address to 0x3F for a 16 chars and 2 line display
/*********************************************************/
String msg = "hallo!";
String info = "this is a message from NASA spacestation!";

void short_msg(String msgs){
    for (int i = 0; i < msgs.length(); i++) {
    lcd.setCursor(i, 0);
    lcd.print(msgs[i]);
    delay(150);
  }
}
TimedAction firstLine = TimedAction(700,short_msg(msg));
TimedAction secondLine = TimedAction(3000,long_msg(info));

void setup()
{
  lcd.init();  //initialize the lcd
  lcd.backlight();  //open the backlight
}
/*********************************************************/
void loop()
{
    firstLine.check();
    secondLine.check();
  //  short_msg(msg);
  //  long_msg(info);
}


void long_msg(String msgs) {
   int s = 16;  //cursor pos
   int t = 0;  // first char to display
   int pad = 0;
   for(int r = msgs.length()+16;r>0;r--){
      if(s>0){
        s--;
      }else{
        t++;
      }
      lcd.setCursor(s,1);
      if(r<=16){
          pad=1;
      }
      if(s>0){
        lcd.print(msgs.substring(0,16-s));
      }else{
        lcd.print(msgs.substring(t,16+t));
      }
      if(pad==1){
        lcd.print(" ");
      }
      delay(300);
   }
}

compile error like this:

display2:27:55: error: invalid use of void expression
TimedAction firstLine = TimedAction(700,short_msg(msg));
^
display2:28:57: error: invalid use of void expression
TimedAction secondLine = TimedAction(3000,long_msg(info));
^
exit status 1
invalid use of void expression

2

Please post a complete sketch illustrating the problem and a link to whatever TimedAction is

3

Looks like its a class that you set a time & function pointer. And it calls that function over and over. i guess you have to call check() over and over in your loop to make it go.

I'd create a global that both function can "see".

Well, no.. I'd use idlers library. But that's just me.

-jim lee

4

How about this:

String msg = "hallo!";
String info = "this is a message from NASA spacestation!";

void short_msg_caller(void)
{
  short_msg(msg);
}

void long_msg_caller(void)
{
  long_msg(info);
}

TimedAction firstLine = TimedAction(700, short_msg_caller);
TimedAction secondLine = TimedAction(3000, long_msg_caller);
5

johnwasser:
How about this:

String msg = "hallo!";

String info = "this is a message from NASA spacestation!";

void short_msg_caller(void)
{
  short_msg(msg);
}

void long_msg_caller(void)
{
  long_msg(info);
}

TimedAction firstLine = TimedAction(700, short_msg_caller);
TimedAction secondLine = TimedAction(3000, long_msg_caller);

thank you!