Exercise-003 Helper function implementation

In this article, we learn how to implement helper functions.

First, display_message. You have to call the first lcd_set_cursor, then call lcd_print_string, as shown below.

static void display_message(String s, uint8_t c , uint8_t r){
    lcd_set_cursor(c,r);
    lcd_print_string(s);
}

display_message function

And for the beep, you have to call the tone function with the pin of the Buzzer; the duration is 25 milliseconds; I mean, the beep will come for 25 milliseconds, a short beep. 4000 is a frequency of square wave generated, which is fed to the Buzzer 4 KHz( as shown below).  

static void do_beep(void){
       tone(PIN_BUZZER, 4000, 25);
}

do_beep function

//////////////////////////helper functions//////////////////////////
static void display_time(uint32_t time){
  char buf[7];
  String time_msg;

  uint16_t m = time / 60;
  uint8_t s = time % 60;
  sprintf(buf,"%03d:%02d",m,s);

  time_msg = (String)buf;
  lcd_set_cursor(5,0);
  lcd_print_string(time_msg);
}

display_time function

In the display_time function, you receive the current time. And that current time is divided by 60 to get the minutes, and then modules (%) with 60 to get the seconds, and then we convert this into a string. The minute and second information. For that, we will use a sprintf function; and we will store that string in the buffer, a character buffer. “%03d:%02d” is the format specifier used. Format specifier will convert m,s numbers to a string format, and that string will be stored in the buffer.

Here I have used ‘%03d’ for the minute, because I need a minute with a width of 3 characters. This generates an integer of width three characters. The unused character will be filled with 0. And same as ‘%02d’. 

And that buffer, I convert it into a string format. The Arduino framework provides this, just typecast that.

And lcd_set_cursor. Before printing the time information, set the cursor first. The column is 5, and the row is 0. And then call lcd_print_string.  

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