Is there any bluetooth module supports both Bluetooth/BLE 5.0 and 4.x at the same time?

Question

The recent mobile phones support BLE 5 and they are backward compatible. That means they can connect to both BLE 5 and 4 devices. When I read specs, I see that BLE 5 is backward compatible as well. What about on device side? If I develop new device with any BLE 5 module, Can I connect it to using a BLE4 supported mobile phone? If not, is there any module that support dual mode? I want my device to work with old devices but I also want to benefit from the BLE5 advantages with BLE5 devices.

Answer 1

Bluetooth versions are fully backwards compatible for all qualified devices, so in general any new device will talk to an old device using the "old" protocols.

The Bluetooth philosophy is that a new spec version always adds features and rarely if ever removes functionality from the old spec version.

So in your example, yes the 5.0 module will retain all 4.x functionality. A 5.0 device is a 4.x device for all intents and purposes.

One obvious but rare exception arises when it comes to optional features, but that doesn't seem to be your case here. Let's assume there is a feature X that is optional both in 4.x and in 5.0. If device A is a 4.x device and implements X, and if device B is a 5.0 device but does not implement X, then obviously A and B cannot use X together.

Also note that "dual mode" means that the device implements both Classic Bluetooth and Low Energy Bluetooth, and has little to do with versions.