i have interfaced RTL8720DN(BW16) module (not development board) with ATMEGA2560 through serial. Previously i tested my application (MQTT) using AMB23 (RTL8722DM MINI) development board. so we gone to our own board with RTL8720DN(BW16) module and controller ATMEGA2560. it works fine and i can able to connect the network, but i cant able to find MQTT commands in the datasheet. Somebody told me to update the firmware, and i find ImageTool from realtek and updated the firmware as they instructed. now i cant able to send AT Commands as the module doesn't response for the AT commands. How shall i roll back the firmware to previous one. if any body have AT commands for RTL8720(BW6) module pls help me.