https://en.wikipedia.org/wiki/Network_i ... .29_attack
To send deauth packets, you need send 802.11 raw packets.
In SDK 1.4.0 there is a function called "wifi_send_pkt_freedom". Maybe this help you. I tried use this function, but no sucess. It always is returning -1 (fail status). Does anyone have any example code (that works) using this function to share with us?