Can a bluetooth 4.0 device send data to a bluetooth 2.0 device?

Question

Is it possible for a Bluetooth 4.0 chip to interact with an Android phone with Bluetooth 2.0 via the Android SDK support for Bluetooth?

Answer 1

Yes - If the 4.0 chip supports dual mode Bluetooth (Bluetooth Low Energy and Standard Bluetooth ) and if they have compatible profiles.

Note - Bluetooth 4.0 can also be single mode (Bluetooth Low Energy only) chips, those devices will not be able to talk to Legacy Bluetooth Devices. These single mode devices will typically be found in sensor devices. Phones will typically have dual mode Bluetooth 4.0

Answer 2

Just as a clarification, dual mode Bluetooth is most commonly called "Bluetooth Smart Ready" in marketing. Single mode Bluetooth, or Bluetooth low energy, is marketed as "Bluetooth Smart".

As the pervious answer indicates, if your module is Bluetooth Smart Ready it will be able to talk to both all older Bluetooth variants (1.1, 2.0, 2.1, 3.0 etc) and the newer Bluetooth Smart devices. However if it is a Bluetooth Smart device it will only be able to communicate with other Bluetooth Smart devices or Bluetooth Smart Ready devices.