As long as I know an iOS device can communicate with BT device if BT device is MFI compliant. But some of my friends says apple no-longer support BT devices after the introduction of BLE devices. What my understanding is an iOS device can communicate with BT device using External Accessory Framework if BT device is MFI compliant? Searched a lot and couldn't find any useful documentation from apple. Any help is greatly appreciated
You can connect to Bluetooth Low Energy (BLE) aka Bluetooth Smart or Bluetooth 4.0 devices using the Core Bluetooth framework. BLE devices are specifically excluded from the MFI program.
Bluetooth 2.1 devices are covered by the external accessory framework and require membership of the MFI program in order for the device to be certified by Apple.
There are a couple of exceptions to this - some standard profiles such as headset, hands free, audio streaming and keyboards are supported without the device bing MFI certified, but you don't interact with these devices at the Bluetooth level - audio devices are managed through the AV framework and keyboards just send their input to text controls in the same way as the onscreen keyboard