Still use Bluetooth 2.1?
IF you are in need of such a 4.0 BLE Bluetooth module, MCU can be set up,also can controlled by a remote Bluetooth device for setting,can transfer data, and can remotely control 10 PIO pins,so,the best choice is HM-10/11 bluetooth module.
HM-11 size is only have 2.4cm X 1.5cm .
HM-11 can work with IOS, PC, Android 4.3 now.
Brand new and high quality.
Send and receive no bytes limit.
The power can be adjusted -23dbm, -6dbm, 0dbm, 6dbm, can modify through AT Command AT+POWE.
Long range, Open space have 100 Meters with iphone4s.
Low Power: Only 0.5 mA for standby, Active 8.5 mA, support auto sleep.
Central & Peripheral in one.
UUID FFE0, FFE1.
Support serial port update firmware (add in V508).
1 x HM-10 CC2541 CC2540 4.0 Bluetooth UART Transceiver Module Transparent Serial Port