Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Fri, 05 May 2023 20:53:45 GMT

Found it. The below defaulted to...

#define CONFIG_BT_L2CAP_TX_MTU 65

#define CONFIG_BT_BUF_ACL_TX_SIZE 27

#define CONFIG_BT_BUF_ACL_RX_SIZE 69

...in the autoconf.h. That's where my 65 limit came from.

In my prj.conf, added the below...

CONFIG_BT_L2CAP_TX_MTU=247

CONFIG_BT_BUF_ACL_RX_SIZE=251

CONFIG_BT_BUF_ACL_TX_SIZE=251

...and like magic...

...I can send even more bytes.

I think our work here is done. Thanks you so much!

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Fri, 05 May 2023 19:58:05 GMT

devzone.nordicsemi.com/.../nrf52840-connect.pcapng

I think this might be what you are looking for.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Fri, 05 May 2023 19:18:19 GMT

Could you capture the sniffer log while you are getting the RTT log?

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Fri, 05 May 2023 18:56:24 GMT

I think we are onto something here. I added the missing code to the connected_cb callback function. I'm not getting a connect event as you describe above but I suggests 63 bytes now instead of the 23 before. At least we are moving in the right direction.

This can now be seen in the RTT Console when I connect.

Question is... where is it picking up this 65 when my default_mtu value in the Python app 250?

I've confirmed that I can now transmit 61 bytes.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Fri, 05 May 2023 17:10:26 GMT

Hi,

From your log, I don't see any connect event. You should see something like this if the center or peripheral requests MTU update.

You should check if the MTU exchange has actually happened or not. In some of our examples where the peripheral is configured to automatically initiate MTU exchange, the Python script central will automatically give a MTU Exchange Response with the value in default_mtu.

If the peripheral does not initiate, then the central has to.

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Fri, 05 May 2023 14:26:28 GMT

I captured these logs. Filter on source d3:f1:4b:b8:32:d6. If you scroll down about half way, that's all you'll see. It advertises Orbis_HQEA100052. It does show 23 bytes which means the Python is ignoring the self.adapter.default_mtu = 250 setting. On Android it shows 53 bytes.

devzone.nordicsemi.com/.../nrf52840-to-nRF52-Dongle.pcapng

devzone.nordicsemi.com/.../nrf52840-to-android.pcapng

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Thu, 04 May 2023 15:36:56 GMT

I'll try again tomorrow when I bring my work laptop in from home.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Thu, 04 May 2023 13:32:25 GMT

You need an extra device to run the sniffer.

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Thu, 04 May 2023 13:23:48 GMT

I did finally get this to work as demonstrated by the below screen shot.

It seems like the nRF52840 Dongle conflicts with all this. If I get my device talking with our tool via the dongle, then WireShark won't display the nRF Sniffer. If WireShark is displaying the nRF Sniffer, I can't connect to the dongle with our tool. It's like I need a separate computer to run the WireShark and the DK board.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Wed, 03 May 2023 20:00:54 GMT

I would suggest to uninstall WireShark, and delet the Wireshark folder under C:\Program Files\Wireshark and C:\Users\YourUserName\AppData\Roaming\Wireshark, and then refer to this guide to install again.

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Wed, 03 May 2023 19:38:34 GMT

Even though I removed the nrf sniffer from the extcap folder, it freezes when the app loads. It's trying to laod an external plugin I deleted. It did the same thing when the external plugin was installed. I've uninstalled WireShark and reinstalled it numerous times. Even deleted the program folder after uninstall. I can't even run the program at this point.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Wed, 03 May 2023 18:43:25 GMT

Which DK and HW version are you using to run the nRF Sniffer? If you are using nRF52840 DK v3.0.0, please use the USB port.

Could you check the steps in Installing the nRF Sniffer capture tool and Adding a Wireshark profile for the nRF Sniffer?

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Wed, 03 May 2023 16:47:53 GMT

That tutorial was what I needed but unfortunately, WireShark becomes unresponsive when trying to load the nrf_sniffer interface. I even tried using the previous stable version. Not sure what to do now.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Wed, 03 May 2023 12:55:47 GMT

Hope this tutorial could help.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Tue, 02 May 2023 19:28:03 GMT

That's what I'm reading and not getting much out of it. I'll try again tomorrow morning.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Tue, 02 May 2023 19:20:38 GMT

Hi,

You can follow the guide to Installing the nRF Sniffer and Running the nRF Sniffer. The nRF Sniffer usage doc would show you how to use it.

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Tue, 02 May 2023 18:42:26 GMT

I installed WireShark and downloaded the sniffer. I've never worked with these tools before and the instructions are written for people with experience. I have no clue what I'm even looking at. No clue how your python app works with WireShark.

I'm surprised there's nothing to this effect already built into your "Bluetooth Low Energy" app in nRF Connect for Desktop.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Tue, 02 May 2023 13:58:53 GMT

Hi,

Maybe you can do a sniffer trace to see if the MTU is actually updated? That should also show if there are other configurations that can cause the limitation. If you could provide the nRF Sniffer log, it could help to investigate the issue.

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Mon, 01 May 2023 14:45:26 GMT

Looks like the defaults are already set to the max.
https://github.com/NordicSemiconductor/pc-ble-driver-py/blob/master/pc_ble_driver_py/ble_driver.py#L1776

There's two observes for the data length but they are not being called. I added the observers but my break points are not getting hit. I can't override the function you highlighted. Not sure where this fixed size of 20 bytes is coming from.
github.com/.../observers.py

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Fri, 28 Apr 2023 17:58:43 GMT

Hi,

You could try to increase the data_length with https://github.com/NordicSemiconductor/pc-ble-driver-py/blob/master/pc_ble_driver_py/ble_adapter.py#L252

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Thu, 27 Apr 2023 13:33:53 GMT

If I am to set the MTU prior to pairing, then how do I accomplish this within python using your pc-ble-driver-py Python package? I wrote a Python tool using your pc-ble-driver-py v0.17.0 to pull test data through BLE but I'm limited to 20 byte packets. The real goal is to not be limited to 20 byte packets. Thought I had to set the dongle for this. Connecting to the the BLE via your Android app nRT Toolbox is not limited to 20 byte packets, more like 60 byte packets.

I set the default MTU to 250 but yet I'm limited to 20 byte packets.

Line 46: self.adapter.default_mtu = 250

Below is the relevant code that directly connects to your Python package. Any ideas?

# Hard code the conn_ic_id because this is the only one we will use
# and the pc_ble_driver_py Python library checks the value
from pc_ble_driver_py import config
config.__conn_ic_id__ = 'NRF52'

from pc_ble_driver_py.observers import *
from pc_ble_driver_py.ble_adapter import BLEAdapter
from pc_ble_driver_py.ble_driver import (
        BLEDriver,
        BLEAdvData,
        BLEEvtID,
        BLEEnableParams,
        BLEGapTimeoutSrc,
        BLEUUID,
        BLEGapScanParams,
        BLEConfigCommon,
        BLEConfig,
        BLEConfigConnGatt,
        BLEConfigConnGap
    )
import time, logging

class NordicBleDriver(BLEDriverObserver, BLEAdapterObserver):
    def __init__(self, comport=None, notificationCallback=None, connectCallback=None, disconnectCallback=None, timeoutCallback=None):
        super(NordicBleDriver, self).__init__()
        self.comport = comport
        self.adapter = None
        self.scanCapture = []
        self.active_conn = {}
        self.notificationCallback = notificationCallback
        self.connectCallback = connectCallback
        self.disconnectCallback = disconnectCallback
        self.timeoutCallback = timeoutCallback

    def open(self, comport=None, conn_count=1):
        '''
        Open the connection to the comport
        '''
        if comport:
            self.comport = comport

        driver = BLEDriver( serial_port=self.comport, auto_flash=False, baud_rate=1000000, log_severity_level="info")
        self.adapter = BLEAdapter(driver)
        self.adapter.observer_register(self)
        self.adapter.driver.observer_register(self)
        self.adapter.default_mtu = 250
        self.adapter.driver.open()
        gatt_cfg = BLEConfigConnGatt()
        gatt_cfg.att_mtu = self.adapter.default_mtu
        gatt_cfg.tag = 1
        self.adapter.driver.ble_cfg_set(BLEConfig.conn_gatt, gatt_cfg)
        gap_cfg = BLEConfigConnGap()
        gap_cfg.conn_count = conn_count
        self.adapter.driver.ble_cfg_set(BLEConfig.conn_gap, gap_cfg)
        self.adapter.driver.ble_enable()

    def close(self):
        '''
        Close the connection to the comport
        '''
        self.adapter.driver.close()
        self.adapter = None

    def scan(self, blocking = True, scan_duration = 5):
        '''
        Scan for other BLE devices
        '''
        self.scanCapture = []
        params = BLEGapScanParams(interval_ms=200, window_ms=150, timeout_s=scan_duration)
        self.adapter.driver.ble_gap_scan_start(scan_params=params)
        if blocking:
            time.sleep(scan_duration)

    def advertise(self):
        '''
        Advertise this BLE
        '''
        adv_data = BLEAdvData(complete_local_name="nordic_ble_driver_py")
        self.adapter.driver.ble_gap_adv_data_set(adv_data)
        self.adapter.driver.ble_gap_adv_start()

    def connect(self, peer_addr, blocking = True):
        '''
        Connect to a peer address
        '''
        self.adapter.connect(peer_addr, tag=1)
        if blocking:
            while(self.adapter.conn_in_progress):
                time.sleep(0.5)

    def disconnect(self, conn_handle):
        '''
        Disconnect from peer address
        '''
        self.adapter.disconnect(conn_handle)

    def disconnectAll(self):
        '''
        Disconnect from peer address
        '''
        keys = self.active_conn.copy().keys()
        for x in keys:
            self.adapter.disconnect(x)

    def discoverServices(self, conn_handle):
        '''
        Discover the services
        '''
        try:
            self.adapter.service_discovery(conn_handle)
        except Exception as e:
            logging.info(str(e))

    def enableNotification(self, conn_handle, uuid):
        '''
        Enable the notifications
        '''
        try:
            self.adapter.enable_notification(conn_handle, uuid)
        except Exception as e:
            logging.info(str(e))

    def write(self, conn_handle, uuid, data):
        '''
        Write data to device
        '''
        try:
            self.adapter.write_req(conn_handle, uuid, data)
        except Exception as e:
            logging.info(str(e))

    def getUUID(self, conn_handle, serviceUUID, charUUID):
        '''
        Get the UUID of the value
        '''
        if conn_handle != None:
            for s in self.adapter.db_conns[conn_handle].services:
                if s.uuid.value == serviceUUID:
                    for c in s.chars:
                        if c.uuid.value == charUUID:
                            return c.uuid
        return None

    def addToList(self, name, peer_addr):
        '''
        Add connect to list keeping out the duplicates
        '''
        found = False
        for x in self.scanCapture:
            if x['name'] == name and get_addr_str(x['peer_addr']) == get_addr_str(peer_addr):
                found = True
                break

        if not found:
            self.scanCapture.append({'name': name, 'peer_addr': peer_addr})

    def on_gap_evt_adv_report(self, ble_driver, conn_handle, peer_addr, rssi, adv_type, adv_data):
        '''
        Observer call back during a scan
        '''

        if BLEAdvData.Types.complete_local_name in adv_data.records:
            self.addToList(bytes(adv_data.records[BLEAdvData.Types.complete_local_name]), peer_addr)

        elif BLEAdvData.Types.short_local_name in adv_data.records:
            self.addToList(bytes(adv_data.records[BLEAdvData.Types.short_local_name]), peer_addr)

    def on_notification(self, ble_adapter, conn_handle, uuid, data):
        '''
        On notification message handler
        '''
        if self.notificationCallback:
            # Send a copy so as to not get over written
            self.notificationCallback(ble_adapter, conn_handle, uuid, data.copy())
        else:
            logging.info("Connection: {}, {} = {}".format(conn_handle, uuid, data))

    def on_gap_evt_connected(self, ble_driver, conn_handle, peer_addr, role, conn_params):
        '''
        On connected message handler
        '''
        # Find the advertised name
        addr = peer_addr.addr
        adv_name = ''
        for x in self.scanCapture:
            if addr == x['peer_addr'].addr:
                adv_name = x['name']
                break

        self.active_conn[conn_handle] = {'adv_name': adv_name.decode(), 'peer_addr': peer_addr.addr}
        if self.connectCallback:
            self.connectCallback(ble_driver, conn_handle, adv_name.decode(), peer_addr, role, conn_params)
        else:
            logging.info("New connection: {}".format(conn_handle))

    def on_gap_evt_disconnected(self, ble_driver, conn_handle, reason):
        '''
        On disconnected message handler
        '''
        if conn_handle in self.active_conn:
            del self.active_conn[conn_handle]

        if self.disconnectCallback:
            self.disconnectCallback(ble_driver, conn_handle, reason)
        else:
            logging.info("Disconnected: {} {}".format(conn_handle, reason))

    def on_gap_evt_timeout(self, ble_driver, conn_handle, src):
        '''
        On disconnected message handler
        '''

        if self.timeoutCallback:
            self.timeoutCallback(ble_driver, conn_handle, src)
        else:
            logging.info("timeout: {} {}".format(conn_handle, src))

    def get_addr_str(self, peer_addr):
        return get_addr_str(peer_addr)

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Thu, 27 Apr 2023 13:06:29 GMT

Hi,

From your screenshot, you are setting the max length of a characteristic to 60. This is not the same as setting the data length of a connection. And in the code snippet, it looks like the MTU is logged, not the data length. To set the Data Length or MTU in the nRF Connect BLE app, see this screenshot:

-Amanda H.

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

GameCodingNinja — Wed, 26 Apr 2023 19:46:01 GMT

Yep, I've done that but that's not the problem. The changes don't seem to be getting saved to the dongle. Even though I changed the max data length to 60, the BLE code in my 52840 still reports 20 when making a connection to the dongle.

Also, see the attached screen shot above.

//
// BLE connected callback
//
static void connected_cb(struct bt_conn *conn, uint8_t err)
{
    char addr[BT_ADDR_LE_STR_LEN];

    if (err)
    {
        LOG_DBG("Connection failed (err %u)", err);
        return;
    }

    bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
    current_conn = bt_conn_ref(conn);

    LOG_INF("Connected %s; Max data length: %u", addr, bt_nus_get_mtu(current_conn));
}

RE: Making changes in "Server Setup" for "nRF52840 Dongle" in "nRF Connect for Desktop Bluetooth Low Energy" doesn't save changes to dongle.

Amanda Hsieh — Wed, 26 Apr 2023 19:26:09 GMT

Hi,

You can save the setup and load it when you need. See Configuring server setup.

Regards,
Amanda H.