It seems SNTP not sync successfully.

Maybe you missed the esp_netif_init(), you can follow https://github.com/espressif/esp-idf/bl ... .c#L70-L73

No, lwip sntp not reproduce a public API to send sntp request. As you saw, it is static and need need maintain some timeout function and state, so stopping sntp module and re-starting it is a easy way to send sntp request.

Do this issue solved? If yes, i will mark it as solved. Or you can comment here when you face the similar issue.

Yes, it will only deinit sntp pcb and initialize sntp pcb again, but will not change configuration you set before, such as operating mode and NTP servers.

It seems the WIFI is connecting. Before you call esp_wifi_connect(), you can call esp_wifi_disconnect() first.

你需要分清 HTTP GET 和 POST 请求的差别。当我们使用 GET 请求时，我们需要发送 HTTP 头并带上 GET 请求（esp_http_client_open），此时对端会把我们请求的数据发送回来，这个时候我们调用 esp_http_client_fetch_headers 是可以读到 HTTP 头数据的。但是当我们是 POST 请求时，esp_http_client_open 只是发送了HTTP 头并带上 POST 请求，并没有发送 POST 数据，服务器是不会回的， POST 数据是后续函数 esp_http_client_write 发给服务器的。你可以把 esp_http...

If I understand correctly, you want to re-send the NTP synchronization request through the API sntp_request instead of internally using a fixed time interval for time synchronization. I think you can try the sntp_restart API.

不是很明白你要表达的意思，你可以直接贴代码或者重新整理下你想要咨询的问题。

这个取决你接收缓存区大小 LWIP_TCP_WND_DEFAULT.