BLE C++ Wrapper

[schef]

I am trying to wrap BLE into a nice c++ class. For this i am using ble_app_uart example. I think it was working fine until i was up to clean the helper functions. After that i got error_code: 8 at SOFTDEVICE_HANDLER_INIT(&clock_lf_cfg, NULL);.

Here is a full example. ble_app_uart_modified.rar

In file ble_wrapper.cpp:626 when i comment command ble_advertising_start there is no error.

I can't seem to find the reason. Is is possible that this is connected to C++ class? Are there some other ideas? Is there a way to narrow the issue?

Thanks.

[Jørgen Holmefjord]

Is the error in SOFTDEVICE_HANDLER_INIT, or from the call to ble_advertising_start? If the error is in SOFTDEVICE_HANDLER_INIT this error means that the stack is allready initialized, you should check that you are not calling this function multiple times. It does not make sense that you get the error in this function, but not if you comment out the proceeding call to ble_advertising_start. If the error is from ble_advertising_start, this means that the advertising module have not been successfully initialized. Where do you instantiate the class in you main.cpp file?

[schef]

in main.cpp:40 is a BLEWrapper::getInstance(); which should call the constructor. And constructor is in ble_wrapper.cpp:30 which calls init:609.

[Jørgen Holmefjord]

Inside ble_advertising_start() there is a call to m_evt_handler(m_adv_evt):588. In advertising_init(), ble_advertising_init() is called with the parameter static_on_adv_evt, which you have implemented as follows:

void BLEWrapper::static_on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
  /* static implementation of on_adv_evt for use with sdk callback function */
  BLEWrapper::getInstance()->on_adv_evt(ble_adv_evt);
}

Since your call to BLEWrapper::getInstance() from main.cpp have not completed, _pInstance have not yet been set, and the check in getInstance():

if(_pInstance == NULL)
{
  _pInstance = new BLEWrapper();
}

will evaluate to true. This will create an infinite loop of new BLEWrapper-instances, and softdevice initialization will fail with error code 8, since it is allready initialized.

You need to refactor your code to start advertising after init, or use another method of getting the instance.

Best regards,

Jørgen

[schef]

Thanks for the anwser. I will have to see how i will solve this issue.

[Sebastien Huet]

Hi @schef did you manage to write your wrapper? may you please share it? thx