wifi_ntp.h File Reference

The clock set from the home network: one SNTP (Simple Network Time Protocol) request a join, through ESP-IDF's esp_netif_sntp. More...

#include <stdbool.h>

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Functions
bool	wifi_ntp_poll (bool joined, bool lingers)
	Move the request on: start it on a join, log and end it on an answer or the time-out, end it when the join ends.
void	wifi_ntp_stop (void)
	End the request before the network interface goes: what wifi_ntp_poll(false, false) does, an answer that came first logged.

Detailed Description

The clock set from the home network: one SNTP (Simple Network Time Protocol) request a join, through ESP-IDF's esp_netif_sntp.

Each join of the home network asks WALL_NTP_SERVER once, in both station modes: the boot release check (WA_MODE_FETCH) and WI-FI's home network (WA_MODE_JOIN). The access point has no route out and asks nothing. The request ends with its answer, after WALL_NTP_TIMEOUT_MS, or with the radio, whichever comes first. A session that ends while the request asks and lingers (wa_lingers(): the release check's own end, the operator's OFF, the idle time-out) holds the radio up until the answer or the time-out (wall_ntp_holds()); every other end takes the radio down at once and ends the request unanswered. An answer sets the system time (lwIP's SNTP calls settimeofday()) and logs one console line: the server, the time set and the offset from the old clock (wall_ntp_line()).

Both calls are the Wi-Fi worker task's. The SNTP client runs in lwIP's TCP/IP (transmission control protocol / internet protocol) task; neither the control task nor the heartbeat waits for any of it.

SPDX-License-Identifier: MIT

Function Documentation

wifi_ntp_poll()

bool wifi_ntp_poll	(	bool	joined,
		bool	lingers )

Move the request on: start it on a join, log and end it on an answer or the time-out, end it when the join ends.

Parameters

joined	The session holds an address on the home network.
lingers	The session ended joined, its radio still up, and lets the radio stay up (wa_lingers()).

Returns

Whether the radio stays up for the request (wall_ntp_holds()).