I'm working with the cheap HC05 BT module.
Networking is no problem at all. Configuration with AT+COMMAND is also clear.
But my hardware send every second around 100 charcters with 9600 Baud and if its not connected its energy consumption is still at 20mA. Thats not an option for a battery powered system. But there are two "functions/parameters" which should be solving this Problem: AT+IPSCAN und AT+SNIFF. But I havent found any datasheet with a documented example of at least one of the both. So it seems to be thats going to be "Trail and Error" Thing :-(
And there is still hope that someone here in the forum may hav a suggestion or already did that.
My hope is on you