Only after the previous packet was sent, and the sent callback is entered, the next packet is allowed to send. Otherwise, wifi_send_pkt_freedom will return “fail”.
How does one setup the sent callback? - I have set up espconn_regist_sentcb() before for TCP, but there does not seem to be such a method dedicated to promiscuous mode and the required espconn_regist_sentcb method requires an espconn structure that can only be configured with a TCP or UDP object. Since promiscuous mode is neither, what do I do? All examples that I have found on the Internet just brute force the wifi_send_pkt_freedom and let it fail... sometime trying multiple times immediately after each other expecting a different answer. I would rather check it being ready and only then create the message to be sent.
Thanks for your help.