error: invalid conversion from 'uint8_t' to 'const char*'

Projects Programming
1

Hi,

I want to display on LCD 2,4'' current day information like this:
"PN 11/11/2015, 13:45"

I am using RTCLib and RTC module DS3231, I have problem with displaying:

 DateTime now = RTC.now(); 
unsigned int dayOfWeek = now.dayOfWeek(); 
    
char* days[8] = {"MO","TU","WE","TH", "FR","SA","SU"};
    
  char * line = "";
  strcat(line,days[dayOfWeek]);
  strcat(line,now.day()); //error: invalid conversion from 'uint8_t' to 'const char*'
    TSC.drawString(line ,  0, 100, 2, WHITE);

How should I convert 'uint8_t' to 'const char*', I am using Arduino IDE 1.5.5 r2

2

You can use itoa or sprintf.

4

Thanks for both answers!

5

I am still having problem with running it.

Serial prints: €ŸöMO2015, MO2015 is ok, but what is before it??

 DateTime now = RTC.now();
  unsigned int dayOfWeek = now.dayOfWeek(); 
      char buffer [10];
    
  char line[70];// = "MO 11/11/2015, 13:45 ";
    
   strcat(line,days[dayOfWeek]);
    itoa (now.year(),buffer,10);
    strcat(line,buffer); 
     
    TSC.drawString(line,  0, 100, 2, WHITE);
7

Your "line" variable is uninitialized:

  char line[70];// = "MO 11/11/2015, 13:45 ";

It can and probably does contain junk.