Hi Jan,
On Wed, Jul 18, 2018 at 06:54:01PM +0200, Jan Clement wrote:
> Hello All,
>
> i tried to get sntp client from lwip stack up and running today and
> stumbled over some little problems and questions i would like to share
> with you:
>
> To start the sntp service I wrote:
>
> sntp_setoperatingmode(SNTP_OPMODE_POLL);
> ip_addr_t ntp_server;
> IP4_ADDR(&ntp_server.u_addr.ip4, 94, 16, 116, 137);//0.de.pool.ntp.org
> sntp_setserver(0, &ntp_server);
> sntp_init();
>
> But the callback function, called by the stack upon receive of the
> packet is defined as follows in lwip/apps/sntp_ops.h:
>
> #if !defined SNTP_SET_SYSTEM_TIME || defined __DOXYGEN__
> #define SNTP_SET_SYSTEM_TIME(sec) LWIP_UNUSED_ARG(sec)
> #endif
It looks like lwIP expects this macro to be defined by the OS (as you
probably inferred!).
> And nothing happens.
>
> So I commented this out, and added
> extern void SNTP_SET_SYSTEM_TIME(uint32_t t);
> to sntp.c.
>
> in my code i defined
> void SNTP_SET_SYSTEM_TIME(uint32_t t) {
>
> ntptime.tv_sec = t * 1000;
> ntptime.tv_usec = 0;
> console_printf("SNTP time from server: %ld \r\n", t);
> os_settimeofday(&ntptime, NULL);
> }
>
> And this works as expected and I get the correct ntp time stamp!
>
> What would be a good and proper way to implement the callback function?
I think your implementation is fine! I would just turn that into a
function (with a lower-case name), and define `SNTP_SET_SYSTEM_TIME` to
call your function.
>
> Another problem is, that os_gettimeofday(&daytime, NULL); gives weird
> results:
>
> 005104 Time = 21474836480
> 006104 Time = 25769803776
> 007104 Time = 30064771072
> 008104 Time = 34359738368
> 009104 Time = 38654705664
> 010104 Time = 42949672960
> 010134 SNTP time from server: 1531932280
> (** syncronization happened)
> 010136 Date: 18.6.2018 16:44:40
>
> after the sync this is the ouput:
> 011104 Time = 6579599043818647160
> 012104 Time = 6579599048113614456
> 013104 Time = 6579599052408581752
> 014104 Time = 6579599056703549048
Hmm, that's odd. How are you printing the `struct os_timeval` value
that `os_gettimeofday` fills in?
Chris
