Hang on BLE connect - custom service SDK13 migration

[kmorris]

I'm migrating from SDK11 to SDK13. My custom service is based off Heart Rate Service, so I started from the new SDK13 example of HRS, and updated all the initialization code following the new example.

Changed: ble_cg.common_cg.vs_uuid__cfg.vs_uuid_count = 2; and adjusted the linker script according to the forum post answer about this.

The issue that comes up appears to occur in the on_connect function within the service. If i comment it out, I can connect, discover services and receive write events. With it implemented, the firmware hangs right after the connection event.

The on_connect function is literally just assigning the conn_handle, is there anything going on behind the scenes in the softdevice at this point?

static void on_connect(ble_cgm_t * p_cgm, ble_evt_t * p_ble_evt)
{
        p_cgm->conn_handle = p_ble_evt->evt.evt.gap_evt.conn_handle;
}

The value of conn_handle is 0. I've tried manually setting p_cgm->conn_handle to 0 at this point as well, and the same thing occurs. Should conn_handle not be 0?

I have tried both with and without the new gatt_evt, just in case that was the issue, but doesn't appear to be it.

Thanks

EDIT: additional code Function where on_connect is called

void ble_cgm_on_ble_evt(ble_cgm_t * p_cgm, ble_evt_t * p_ble_evt)
{
    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            on_connect(p_cgm, p_ble_evt);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            on_disconnect(p_cgm, p_ble_evt);
            break;

        case BLE_GATTS_EVT_WRITE:
            on_write(p_cgm, p_ble_evt);
            break;

        default:
            // No implementation needed.
            break;
        }
}

the ble_cgm_on_ble_evt handler is called from a higher level handler: cgm_on_ble_evt (shown below), which is called directly from ble_evt_dispatch

void cgm_on_ble_evt(ble_evt_t * p_ble_evt)
{
	switch (p_ble_evt->header.evt_id)
    {
		case BLE_GATTS_EVT_HVN_TX_COMPLETE: //depreciated: BLE_EVT_TX_COMPLETE:
			if (sending)
			{
				if(data_ready)
					continueDataSend();
			}
			else
			{
				if (backwards && (sendingStart-sendingLength) > sendingEnd)
				{
					sending = true;
					dataSyncSendBackward(sendingEnd, (sendingStart-sendingLength));
				}

				if (!backwards && (sendingStart+sendingLength) < sendingEnd)
				{
					sending = true;
					dataSyncSendForward((sendingStart+sendingLength), sendingEnd);
				}
			}
		break;
	}
	ble_cgm_on_ble_evt(&m_cgm, p_ble_evt);
}

This handler (cgm_on_ble_evt) is at the level where m_cgm is defined

ble_cgm_t m_cgm;				/**< Structure used to identify the CGM service. */

And the ble_cgm_t structure looks like this.

/**@brief Service structure. This contains various status information for the service. */
struct ble_cgm_s
{
    ble_cgm_evt_handler_t        evt_handler;          /**< Event handler to be called for handling events in the Service. */
    uint16_t                     service_handle;       /**< Handle of the CGM Service (as provided by the BLE stack). */
    ble_gatts_char_handles_t     lsm_handles;          /**< Handles related to the Live Stream characteristic. */
	ble_gatts_char_handles_t     data_handles;         /**< Handles related to the Data Sync characteristic. */
    ble_gatts_char_handles_t     cmd_handles;          /**< Handles related to the Command characteristic. */
	ble_gatts_char_handles_t     stat_handles;         /**< Handles related to the Status characteristic. */
    uint16_t                     conn_handle;          /**< Handle of the current connection (as provided by the BLE stack) */  
	uint8_t						 uuid_type;            /**< UUID type for the CGM Service. */
	ble_cgm_cmd_write_handler_t  cmd_write_handler;    /**< Event handler to be called when the CMD Characteristic is written. */
	//uint8_t                      max_cgm_len;          /**< Current maximum CGM Packet length, adjusted according to the current ATT MTU. */
};

Does ble_cg.common_cg.vs_uuid__cfg.vs_uuid_count need to account for each CHAR UUID?

[FormerMember]

The first connection will have connection handle '0'. And, it should not be a problem assigning a connection handle to '0', a connection handle is just a reference for the application to the various connections.

What does the code calling on_connect() look like?

When calling on_connect(), how is the input parameter p_cgm defined?

What does the struct ble_cgm_t look like?

[FormerMember]

I guess this will not change anything, but could you move ble_cgm_on_ble_evt() out of cgm_on_ble_evt() and call ble_cgm_on_ble_evt() directly from ble_evt_dispatch() instead, and check if it changes anything?

If you run the chip in debug mode, and stop the process when the chip is hanging, where does the chip stop?

What happens if you set a breakpoint in the on_connect() function when ble_cgm_on_ble_evt() is placed inside cgm_on_ble_evt()?