bug in time.c wiced_time_get_iso8601_time() function

[Anonymous]

This wiced_time_get_iso8601_time() does not do a bitwise AND of a number that is frequently greater than 65000, when it converts to a uint16_t. Consequently the result is normally wrong.

Specifics: the local variable uint16_t sub_second is computed as follows. You should always have "000" on the end of the final result, because you take a millisecond value and convert it to microseconds by multiplying by 1000.

wiced_time_get_utc_time_ms( &utc_time_ms );

second     = utc_time_ms / 1000;               /* Time is in milliseconds. Convert to seconds */
sub_second = (uint16_t) (( utc_time_ms % 1000 ) * 1000 ); /* Sub-second is in microseconds               */

/************** Code corrected with int temp variable ***********************/
    temp = (int) (utc_time_ms & 0xFFFF);
    temp = (temp % 1000) * 1000;
    printf("******* temp: %d; sub_sec: %d\r\n", temp, sub_second);
  

/************ temp and sub_second should be identical, but they almost never are.

Code extracted from WICED version 3.1.2

******/

[Anonymous · Accepted solution]

The real problem is that uint16_t isn't big enough to hold numbers up to 1000000 so sub_second needs to be a uint32_t. The modulus(%) operator limits the result to integers less than 1000000, so I don't think you need the bitwise AND (&). The following should always work:

uint32_t  sub_second;

sub_second = (uint32_t) (( utc_time_ms % 1000 ) * 1000 ); /* Sub-second is in microseconds */