HM-10 pairing problem

Hello.

I recently bought HM-10. I was very eager to try to work with Bluetooth 4.0. But I run into a problem. I have to old smartphones (Nokia 603 (Symbian), Lenovo (Android 4.2)) and notebook Asus (Core I7; Windows 8.1). None of them see my Bluetooth.

I did not try much with Nokia, but I tried to install "Bluetooth 4.0 search" on Lenovo and I failed since my Android version is too low. There are some reasons why I can not perform an upgrade of Android.

I installed BlueSoleil on Asus and bought ST-Lab B-421 Bluetooth 4.0 adapter. I can't find my Bluetooth from my notebook.

So, I bought another BLE HM-10 from another vendor. And they paired! But my second device do not response to AT commands... The first one does.

The first HM-10 has four pins Vcc, Gnd, Rx, Tx; the second one has six: Vcc, Gnd, Rx, Tx, State, Brk. I do not connect State and Brk to anything.

So my questions are:

  1. Do I do something wrong with connection of second HM-10 so it does not respond to AT commands?

  2. Can I see and pair my HM-10 from my hardware somehow? I need to write an apk for Android that connects Arduino Due to HM-10.

  3. If I write the Android apk using hm-05 bluetooth 2.0 will this apk work without change with HM-10? If not will I have to do only minor changes?

Thank You very much for the answers in advance.