How to override or detect SNTP_SET_SYSTEM_TIME_US?

[vonnieda]

Hi all,

I am using the SNTP module that comes with ESP-IDF / LWIP. It's working well, but I need to know when it has received a time update and set the time. When it does, it calls SNTP_SET_SYSTEM_TIME_US which is defined in $IDF_PATH/components/lwip/include/lwip/port/lwipopts.h.

Is there any way to override this and use my own function, or at least to be notified when it's called so I can do housekeeping?

Thanks,
Jason

[loboris]

I've needed the same thing and ended up adding the global variable sntp_is_synced which is set to true before calling SNTP_SET_SYSTEM_TIME_US in "sntp.c".
Not a very elegant solution because I've modified the file in the esp-idf, but it works fine.

[vonnieda]

I've needed the same thing and ended up adding the global variable sntp_is_synced which is set to true before calling SNTP_SET_SYSTEM_TIME_US in "sntp.c".
Not a very elegant solution because I've modified the file in the esp-idf, but it works fine.

Thanks loboris, I was hoping to avoid modifying esp-idf, but it does seem like that's the only option.

Thanks,
Jason

[markwj]

I'm going to try to get a change to add an extensible callback mechanism added to ESP IDF master. In the meantime, we'll do it in our own clone.

[markwj]

I have implemented something to deal with this in a standard way, and it works well for my use-case. I ended up simply moving the SNTP_SET_SYSTEM_TIME_US(t, us) into a sntp_setsystemtime_us(u32_t t, u32_t us) weak linked function (as well as doing the same with SNTP_SET_SYSTEM_TIME and sntp_setsystemtime, for completeness). That works well, and is easily overridable in user application code.

Code: Select all

extern "C"
  {
  void sntp_setsystemtime_us(uint32_t s, uint32_t us)
    {
    ... settimeofday ...
    }
  }

https://github.com/espressif/esp-idf/pull/1668

[vonnieda]

I have implemented something to deal with this in a standard way, and it works well for my use-case. I ended up simply moving the SNTP_SET_SYSTEM_TIME_US(t, us) into a sntp_setsystemtime_us(u32_t t, u32_t us) weak linked function (as well as doing the same with SNTP_SET_SYSTEM_TIME and sntp_setsystemtime, for completeness). That works well, and is easily overridable in user application code.

Code: Select all

extern "C"
  {
  void sntp_setsystemtime_us(uint32_t s, uint32_t us)
    {
    ... settimeofday ...
    }
  }

https://github.com/espressif/esp-idf/pull/1668

This looks great, thank you! Looking forward to this getting merged!