Unclear how to stop and restart BLE SD

[matthew antonelli]

I hope that someone can show a clear example of this.  I surprised that it isn't in the SDK examples. Basically, it is necessary to stop the BLE SD, in most low-power examples (if your device is to sleep correctly) then an example should show this clearly.  One shouldn't have to hunt around for such a simple thing as turning itself off!
There should be an example of start and stop that works in the SDK.  Ok.  Enough of the rant.

I'm trying to shut down the BLE, and have cobbled together numerous examples. Right now the following function is being run

void bluetooth_sleep(void)
{
uint32_t err_code;

// If connected, disconnect
if (m_conn_handle != BLE_CONN_HANDLE_INVALID)
{
err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
if (err_code != NRF_SUCCESS) {sprintf(outputString,">>ble disconnect failed\r\n");SEGGER_RTT_WriteString(0,outputString);}
}

// Stop advertising
err_code = sd_ble_gap_adv_stop(m_conn_handle); // WHAT PARAMETERS TO PASS HERE????
if (err_code != NRF_SUCCESS) {sprintf(outputString,">>ble adv stop failed\r\n");SEGGER_RTT_WriteString(0,outputString);}

// Disable the radio tasks as scytulip suggested
// devzone.nordicsemi.com/.../
NRF_RADIO-> POWER =0;
NRF_RADIO->TASKS_DISABLE =1;
}

But this returns 00> <error> app: SOFTDEVICE: INVALID MEMORY ACCESS in the RTT. 

I think that the parameters that are being passed are wrong, but because all the structures for the GATT advertising is run in macros, it is outside my source code...

[Vidar Berg]

Hello,

There should not be any difference if you enter sleep with or without the Softdevice enabled. Are you trying to enter System ON mode or System OFF mode(aka deep sleep)?

Our BLE peripheral examples in <sdk_root>\examples\ble_peripheral\ are already configured to enter System ON mode between Softdevice and Application events by calling the idle_state_handle() function from the main loop.  If you are looking to reduce the current to the minimum in system ON mode and don't need BLE, then you just need to ensure the Softdevice isn't performing any tasks by terminating any active connections and stop advertising/scanning. You should also make sure logging over UART is turned off (NRF_LOG_BACKEND_UART_ENABLED == 0) as the UART peripheral will have some impact on the idle current.

But this returns 00> <error> app: SOFTDEVICE: INVALID MEMORY ACCESS in the RTT. 

 This assertion is raised by the Softdevice's Memory isolation and runtime protection because you were accessing the RADIO registers while the Softdevice was enabled. But there is no need to disable the RADIO. The Softdevice does this internally after every BLE protocol event anyway (Bluetooth Low Energy power profiles).

err_code = sd_ble_gap_adv_stop(m_conn_handle); // WHAT PARAMETERS TO PASS HERE????
if (err_code != NRF_SUCCESS) {sprintf(outputString,">>ble adv stop failed\r\n");SEGGER_RTT_WriteString(0,outputString);}

You are supposed to pass the same advertising handle that was used when you called sd_ble_gap_adv_start() as this message sequence chart shows:

(sd_ble_gap_adv_stop)

But it's also ok to pass '0' here.  The current Softdevices do not support multiple advertising handles.

Best regards,

Vidar