How to debug NRF_ERROR_INVALID_STATE easily?

Question

Hello, 
 I receive NRF_ERROR_INVALID_STATE error quite a few times because my own state handling is still a little buggy. I want to find all these errors. What would be the best way to debug this.
Is there any possibility to read the current state of the softdevice?
I am currently calling sd_ble_gattc_characteristics_discover after I received the BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP event. This results in an invalid state and I am not quite sure why this would happen.
I would be very interested in getting the current state and maybe a possibility if advertising and/or scanning are currently switched on or if a connection is in progress,etc...
The more information I can get from the SoftDevice (S130 0.9-alpha), the better. 
 Thanks a lot,
Marius

Marius Heil · Accepted Answer

Hello, 
 here is my code that I call upon receiving the BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP event: 
 void _bleServiceDiscoveryFinishedHandler(ble_evt_t* bleEvent){
	u32 err = 0;
	
	//Service has been found
	if(bleEvent->evt.gattc_evt.params.prim_srvc_disc_rsp.count > 0){
 if(debugPlainC) tracel("Found service");
 
 //Service handle range has been found, now start discovery on characteristics
 ble_gattc_handle_range_t handleRange;
 handleRange.start_handle = bleEvent->evt.gattc_evt.params.prim_srvc_disc_rsp.services[0].handle_range.start_handle;
 handleRange.end_handle = bleEvent->evt.gattc_evt.params.prim_srvc_disc_rsp.services[0].handle_range.end_handle;
 
 err = sd_ble_gattc_characteristics_discover(bleEvent->evt.gap_evt.conn_handle, &handleRange);
 APP_ERROR_CHECK(err);
	}
}
 
 However I only received this error once while I was debugging and it has never occured again since. Maybe I have an error in that code snippet or maybe it was something else. I have just switched over from KEIL to developing with Eclipse and GCC.