HM-10 clone (BLE-CC41-A) reboot problem + solution

Tim Schuerewegen

Other Parts Discussed in Thread: CC2541

A few days ago I received a HM-10 clone (BLE-CC41-A) and flashed it with SBL + HostTestApp.

When I provide the board with power, the bootloader executes and jumps to the HostTestApp code, and HCI over UART commands work, no problem. However, when HostTestApp is running and I issue a HCI_EXT_ResetSystemCmd or UTIL_ForceBoot command, the board locks up. If I then send exactly 16 garbage bytes over UART, the board resets/continues on reception of the 16th byte, and everything works again. The same happens when I issue the "enable" command when in bootloader mode, the board locks up, I send 16 bytes, and it works again.

After some investigation (by increasing SBL size to 4K and using LED flashes to tell me what it was doing) I discovered that the problem was being caused by a missing 32 Khz external crystal. The original HM-10 has one but the clone I have (BLE-CC41-A) doesn't. The solution is very easy. Change the SET_32KHZ_OSC() define in hal_board_cfg.h so that it selects the internal 32 Khz oscillator instead of the non-existing external one.

I flashed the new SBL + HostTestApp and the board can now jump from HostTestApp to SBL and vice versa without any lockups.

over 9 years ago

J Lindh over 9 years ago

TI__Guru 57865 points

Hi Tim,
Thank you for sharing this information.

Best Regards
Joakim

Jim Seymour over 9 years ago

Intellectual 620 points

One more tidbit: In the current code, it seems you can accomplish this without modifying hal_board_cfg.h. On the CC2450, set the preprocessor directive "XOSC32K_INSTALLED=FALSE" and on the CC2541, set "OSC32K_CRYSTAL_INSTALLED=FALSE".

Or were your changes more involved than this?

Tim Schuerewegen over 9 years ago in reply to Jim Seymour

Prodigy 55 points

No. That should work too.

Davor Dundovic over 9 years ago

Prodigy 20 points

Hi Tim,
I have some problems with the same module i.e. I can't communicate with it at all over RS232.
Could you help me perhaps? I'm not sure whether the module is faulty or is just asleep and I can't wake it.
If you have a bit of good will and time I would appreciate if you would contact me on davor.dundovic@gmail.com not to spam this thread.

Jim Seymour over 9 years ago in reply to Davor Dundovic

Intellectual 620 points

I almost mentioned in my earlier post that I had to turn off POWER_SAVING in order for my UART to work. You might want to go into your compiler options and check your preprocessor directives. If "POWER_SAVING" is there, put an "x" in front of it and retry your code.

Now, if you NEED power saving, then I don't have any help to offer...

Mansour Behabadi over 9 years ago

Prodigy 10 points

Could you tell me how you wired up the module to be able to use SBL to load new firmware on it?

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HM-10 clone (BLE-CC41-A) reboot problem + solution