Web socket - Send asynchronous message from server to client without request from client

[lukecam95]

Hi,

In the esp-idf included example ws_echo_server.c I cannot understand how the server can send a message to the client without the client sending a request previously. The function

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trigger_async_send(httpd_handle_t handle, httpd_req_t *req)

requires the client to send a request first. Also, the function:

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 httpd_ws_send_frame(httpd_req_t *req, httpd_ws_frame_t *pkt)

requires a existing request to be received so I cannot just send a packet.

Can somebody please clear this up please.

Regards,
Luke

[ESP_YJM]

You can use API

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esp_err_t httpd_ws_send_frame_async(httpd_handle_t hd, int fd, httpd_ws_frame_t *frame);

For this API, you need record the fd in the previous connection.

[lukecam95]

Thanks that did the trick

[w4d4f4k]

but if we run this in loop then user can not send no more requests.. is possible to increase number of connections for client..? maybe to run with xTaskCreate.. will try and noticing.

[w4d4f4k]

so yes it works with xtaskcreate and to save socket somewhere..