https://github.com/yostane/arduino-at-09/blob/master/hm-10-datasheet.pdf
https://medium.com/@yostane/using-the-at-09-ble-module-with-the-arduino-3bc7d5cb0ac2
http://www.martyncurrey.com/hc-05-with-firmware-2-0-20100601/
HC-05 with 2.0-20100601: Main AT Commands
AT+UART=baudRate,stop,parity
i.e. “AT+UART=38400,0,0″
4800 9600 19200 38400 57600 115200 230400 460800 1382400
stop is the stop bit. Either 0 or 1 parity is the parity but. Either 0, 1, or 2. 0 = none. 1 = odd. 2 = even.