How to convert integer to string?

[antonius]

Posted on January 02, 2014 at 11:47

struct tm time;

   char year[50]; Guys, I want to display year into LCD screen but I got 00 on LCD, any clues on how to do it ? thanks  printf(''Time: %d-%d-%d   %02d:%02d:%02d \r\n'', time.tm_year, \                    time.tm_mon+1, time.tm_mday,\                    time.tm_hour, time.tm_min, time.tm_sec);     sprintf(year,''%.2f'',time.tm_year);     lcd_string(year); #!complicated

[Tesla DeLorean]

Posted on January 04, 2014 at 15:59

Then you'll need to review the lcd_string() code, but it's clearly not going to accept an integer as a parameter if it is expecting a string.

[trevor23]

Posted on January 04, 2014 at 16:38

You previously said that ''00'' was appearing on the LCD. Is this for any string you send e.g. if you used LCD_string(''35'') would it display 35 as expected or would it display ''00''?

You need to be more specific and describe exactly what does and what does not work.

[antonius]

Posted on January 05, 2014 at 06:24

Yes it was displaying 00 before.....

Here's the time variable I have : struct tm {     int tm_sec;   /* seconds after the minute, 0 to 60                      (0 - 60 allows for the occasional leap second) */     int tm_min;   /* minutes after the hour, 0 to 59 */     int tm_hour;  /* hours since midnight, 0 to 23 */     int tm_mday;  /* day of the month, 1 to 31 */     int tm_mon;   /* months since January, 0 to 11 */     int tm_year;  /* years since 1900 */     int tm_wday;  /* days since Sunday, 0 to 6 */     int tm_yday;  /* days since January 1, 0 to 365 */     int tm_isdst; /* Daylight Savings Time flag */     union {       /* ABI-required extra fields, in a variety of types */         struct {             int __extra_1, __extra_2;         };         struct {             long __extra_1_long, __extra_2_long;         };         struct {             char *__extra_1_cptr, *__extra_2_cptr;         };         struct {             void *__extra_1_vptr, *__extra_2_vptr;         };     }; }; lcd_string code : void lcd_string(unsigned char *str){          while(*str){         lcd_data(*str++);     }      }

[antonius]

Posted on January 05, 2014 at 07:22

it displays something already, in unix time :

the code : sprintf(year,''%2d'',time.tm_year); lcd_cmd(LCD_CLEAR); lcd_string(''YEAR: ''); lcd_string(year); vTaskDelay(15000); on LCD, now another puzzle for me for converting that value to 2...any clues ? thanks ________________ Attachments : IMG_20140105_141247.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I19a&d=%2Fa%2F0X0000000bj7%2F7xud0rBkhUeZnRi2iOXedL7qX1qOyN9qS2hdz8_ETEg&asPdf=false

[Tesla DeLorean]

Posted on January 05, 2014 at 07:59

any clues ?

One might reasonably assume the structure simply doesn't contain what you want it too?

time.tm_year

= 1234; // try setting it explicitly

sprintf(year,''%2d'',time.tm_year);

               lcd_cmd(LCD_CLEAR);                lcd_string(''YEAR: '');                lcd_string(year);                vTaskDelay(15000); I'll observed that printf/scanf functions are stack hogs, and that issues can occur with the locale if they collide. Understand your stack size allocation, and actual usage.

[aa_talaat]

Posted on January 05, 2014 at 18:22

Hi,

This is the routine I am using to display integers on my Nokia 5110 LCD in case it can be of any help. It displays up to 5 digits, and you can control the number of digits to display based on the last parameter passed. So, for a day, the digit_num is 2 and for a year, the digit_num is 4.

/*
* Takes an integer and display it as ascii on the LCD
* state: normal or reverse Video
* leading: how may digits to display from the right side
* if zero that means display the full number without leading zeros
*/
void LCD5110_Write_Dec(uint16_t b, uint8_t state, uint8_t digit_num)
{
unsigned char datas[5],i,j;
datas[0] = b/10000;
b = b - datas[0]*10000;
datas[1] = b/1000;
b = b - datas[1]*1000;
datas[2] = b/100;
b = b - datas[2]*100;
datas[3] = b/10;
b = b - datas[3]*10;
datas[4] = b;
datas[0]+=48;
datas[1]+=48;
datas[2]+=48;
datas[3]+=48;
datas[4]+=48;
/* find the first non zero digit to display - display at least one digit */
for (i = 0; i < 
5
; i++) {
if (datas[i] != 48) {
break;
}
}
if (digit_num > 0 && digit_num < 6){ // valid range
i = 5-digit_num;
}
for (j = i; j < 5; j++) {
if (state == NORMAL) {
LCD5110_write_char(datas[j]);
} else {
LCD5110_write_char_rev(datas[j]);
}
}
}

[antonius]

Posted on January 05, 2014 at 23:35 Thanks for the clue, I'll try it....

[antonius]

Posted on January 05, 2014 at 23:37 Is the 5110 LCD like this one ?

http://www.ebay.com.au/itm/Model-Durable-84-48-LCD-Module-White-backlight-adapter-pcb-for-Nokia-5110-N4U8-/390629169570?pt=AU_MobilePhoneAccessories&hash=item5af35019a2

If you don't mind, can I have the initialization code, please ? thank you

[antonius]

Posted on January 06, 2014 at 06:30

yea, it's working, displaying 1234......so what do I miss here ?

Here's the variable I have here : struct tm {     int tm_sec;   /* seconds after the minute, 0 to 60                      (0 - 60 allows for the occasional leap second) */     int tm_min;   /* minutes after the hour, 0 to 59 */     int tm_hour;  /* hours since midnight, 0 to 23 */     int tm_mday;  /* day of the month, 1 to 31 */     int tm_mon;   /* months since January, 0 to 11 */     int tm_year;  /* years since 1900 */     int tm_wday;  /* days since Sunday, 0 to 6 */     int tm_yday;  /* days since January 1, 0 to 365 */     int tm_isdst; /* Daylight Savings Time flag */     union {       /* ABI-required extra fields, in a variety of types */         struct {             int __extra_1, __extra_2;         };         struct {             long __extra_1_long, __extra_2_long;         };         struct {             char *__extra_1_cptr, *__extra_2_cptr;         };         struct {             void *__extra_1_vptr, *__extra_2_vptr;         };     }; };

[Tesla DeLorean]

Posted on January 06, 2014 at 07:21

yea, it's working, displaying 1234......so what do I miss here ?

Whatever is initializing the structure, doesn't seem to be doing it's job.