Can a Bluetooth LE powered device discover a classic Bluetooth device and vice-versa?
bluetooth, bluetooth-lowenergy
Solution
The answer depends on if you mean Bluetooth v4.0 device, or BLE device, the two are not the same.
Bluetooth v4.0 = Classic Bluetooth + Bluetooth High Speed + Bluetooth Low Energy
Therefore, Bluetooth Low Energy is only a subset of Bluetooth v4.0. If your question is regarding Bluetooth v4.0 phones (generally phones are not BLE only), then the answer is Yes, Bluetooth v4.0 mobile phones can theoretically discover Bluetooth v3.0 devices and lower.
Problem
I'm wondering if Bluetooth 4.0 (low-energy) mobile phones could discover classic Bluetooth devices (3.0 and lower), and vice-versa. All I am interested in is discovering the "friendly names". EDIT: As I have understood the replies of this post, Bluetooth 4.0 can discover classic Bluetooth devices but not the other way around. Then my follow-up question is, can a Bluetooth 4.0 device in LE mode discover classic Bluetooth devices?