BT connection problem

[Altix]

I have a bunch of different BT modules, amongst them several cheap HC-06 from ebay as well as the module from Flyduino. After a lot of squeezing Google for a while, I got most problems solved with the exception of one:

All modules can be programmed via Putty (e.g. OK on AT command)
All modules are runnig on 57600 baud (I have an additional 433MHz telemetry which is running on that baud rate and shall be used alternatively)
All modules are set on "Parity None"
All modules can be used to programm an AQ6 or M4 via PC by the GCS without any problem
Only a single one is properly working with the android app (set to BT, 57600 baud), whereas the others refuse to build up a connection.

Does anybody have an idea about tthe magic command, that will make the other work together with the app?

[sandmen]

Is binding working, with all BT modules?

[Altix]

Yes, with the BT dongle in my PC as well as with my smartphone (at least according to "Settings" after entering "1234")

[kinderkram]

Flow control is "off"?
Did you try to use 115k changed by AT commands?
I once had a module that refused to work properly with anything lower or higher than that for unknown reasons.

[Altix]

[kinderkram]

[aBUGSworstnightmare]

[Altix]

[aBUGSworstnightmare]

[Altix]

No problem with OT Jörg I was aware of the risk after reading about your experience with the 300 sized quad. Mine is even a bit smaller, its a typical 250 sized MiniH (MN1806 type motors, KISS ESCs and 6" props, 3S 1800mAh LiPo, AUW inkl. FPV equimpent about 530g) like those very popular BreakOut quads. So I landed after a few seconds (as the little devil was't flyable anyway) and checked the temperature. The base of all motors were very warm but not critically hot. But ist was clear, that I shouldn't continue. Thanks for the PIDs. I'll have look at them and hopefully understand a bit more, which parameters shall be changed and why (the AQ documentation ist quite weak in that point, unfortunately).

Coming back to the BT module, I noticed another thing, which is a bit strange to me. I can build up a connection between the MiniH and the smartphone app, change and save parameters without a problem. On both test flights I did so far, I had to land quite quickly due to the heavy shaking of the quad. In both cases, the BT module turned down before landing, the connection was broken and the little red led on the module had turned off. After disconnecting and reconnecting the LiPo, everything was fine again. The BT module is a simple HC-06 Linvor V1.8, which is specified for voltages between 3,6V and something around 6V (?). Could the voltage output of your expansion board cause the turn off of the module, or which other reasons might be responsible for that?