Hi Jamie,

All the disconnects are Host Bluetooth stack initiated. I will need some help from BlueZ guys to throw some light here.

Regards,

Vinayak

Hi Vinayak

> A btmon log would help identify the reason for disconnection.

I have uploaded the 2 logs here: https://www.dropbox.com/s/d2yurf6nxee9wk0/btmon_logs.zip?dl=0

The Zephyr one has quite a lot at the beginning before I made the connection. Here is one of the disconnect events from the zephyr log file:

< HCI Command: Disconnect (0x01|0x0006) plen 3           #624 [hci0] 292.906310

        Handle: 0

        Reason: Remote User Terminated Connection (0x13)

> HCI Event: Command Status (0x0f) plen 4                #625 [hci0] 292.907421

      Disconnect (0x01|0x0006) ncmd 1

        Status: Success (0x00)

> HCI Event: Disconnect Complete (0x05) plen 4           #626 [hci0] 292.923423

        Status: Success (0x00)

        Handle: 0

       Reason: Connection Terminated By Local Host (0x16)

@ MGMT Event: Device Disconnected (0x000c) plen 8    {0x0002} [hci0] 292.923459

        LE Address: DC:59:20:76:11:5C (Static)

        Reason: Connection terminated by local host (0x02)

@ MGMT Event: Device Disconnected (0x000c) plen 8    {0x0001} [hci0] 292.923459

        LE Address: DC:59:20:76:11:5C (Static)

        Reason: Connection terminated by local host (0x02)

> > the connection parameter update still fails but even minutes later I am still connected to the remote device.

>

> This is weird, the cypress dongle did not perform connection parameter update, update procedure on air only either succeeds or disconnects (unless it’s a connection parameter request procedure that is rejected by peer).

Yes, that is what it is, apologies:

> ACL Data RX: Handle 0 flags 0x02 dlen 16                #179 [hci0] 69.454378

      LE L2CAP: Connection Parameter Update Request (0x12) ident 2 len 8

        Min interval: 6

        Max interval: 12

        Slave latency: 0

        Timeout multiplier: 400

< ACL Data TX: Handle 0 flags 0x00 dlen 10                #180 [hci0] 69.454425

      LE L2CAP: Connection Parameter Update Response (0x13) ident 2 len 2

        Result: Connection Parameters rejected (0x0001)

Thanks,

Jamie

Hi Jamie,

A btmon log would help identify the reason for disconnection.

> the connection parameter update still fails but even minutes later I am still connected to the remote device.

This is weird, the cypress dongle did not perform connection parameter update, update procedure on air only either succeeds or disconnects (unless it’s a connection parameter request procedure that is rejected by peer).

Regards,

Vinayak

Hi Vinayak

I gave it a try this morning with the latest master build of zephyr using the HCI_USB on an nrf52840_pca10059 dongle and I don’t get the errors/timeout issues as I save previously when I tested, however, GATT is unusable from bluetoothctl on linux (BlueZ 5.50). With the zephyr dongle, the device connects, seems to fail a connection parameter updates and disconnects – I am unable to list any details from the GATT server on the remote device (nothing comes through automatically and in the gatt menu, list-attributes seemingly does nothing). In comparison with a non-zephyr (cypress) based USB HCI dongle, it connects and instantly lists the GATT table, the connection parameter update still fails but even minutes later I am still connected to the remote device.

When I tested previously with a UART, it was with flow hardware control wired up to the FTDI chip. If zephyr was set to use it or not I cannot recall (it would have been the default for the HCI_UART example).

Thanks,

Jamie

Hi, Both Mayank and Jamie,

I am interested in the way the HCI packets are transported to the Host Bluetooth stack.

In case of use of nRF DKs and Dongle, if using JLink debugger host firmware, you need to disable the Mass storage device (I don’t remember, it is something to do with 64-byte USB frames).

Hence, my request to try with MBED debugger host firmware which is a different UART to USB implementation.

In case using custom UART to USB, like FTDI, do you wire the CTS/RTS and using hardware flow control?

Same for the TTL connections, correct CTS/RTS and hardware flow control is essential.

The rationale being, observed HCI timeout and HCI framing errors indicate corrupted UART traffic.

Regards,

Vinayak

Hi,

Today’s meeting minutes:

https://docs.google.com/document/d/1IQKBK-GcJNZG0O9QArqYfvb6Huk5xHscN-XIGEZr-z8/

Notes/Minutes

Status updates

• Status update from Wayne regarding PR#22668
• Status and work done / challenges / improvements are well described in the PR https://github.com/zephyrproject-rtos/zephyr/pull/22668
• Main points are
• Improve documentation in Zephyr on how to pass first compiler check in CMake
• What compile optimization are mandatory and which are optional
• Why are certain gcc extensions used

Would be nice to know the reason / get explanation

• Linker:
• Linker primitives not supported in MWDT

• Status update from Thomas regarding IAR: Nothing new. regarding PR#22668

General discussion regarding toolchain support

• CI support for commercial / other toolchains
• For Metaware, CI would need the toolchain install and thus Zephyr community needs a license
• A practice must be established with regards to commercial toolchain licenses which also satisfies vendor requirements
• It will not be practical to run CI with all commercial toolchains supported.
• Vendor of toolchain must be responsible for testing samples with the toolchain
• Dedicate CI to run PR touching toolchain / manually run
• Zephyr community should create a dedicated toolchain test that can verify basic toolchain functionality is working
• Toolchain oriented test cases
• IAR open to contribute static analysis tools, C-STAT to Zephyr
• This is part of IAR compiler when having correct license

• Linker Meta-language / templating
• Find inspiration in how mbed / TF-M / cmsis does linking template.
• TF-M has support for: IAR, clang, gcc (Requires vendor specific templates)
• Mbed has support for three compiler: IAR, Arm compiler 6 (LLVM), gcc
• Work must be expected in Zephyr regarding special gnu linker flags, as example: --whole-archive
• Offset calculation may be confusing to some compilers, see action point.
• The way gperf is used inZephyr linking stages is very hard to do in other linkers.

• Short term goals:
• Dedicated toolchain test cases, 
• DTS
• Kconfig
• Linker
• Label PR for automatic execution of CI Toolchain test cases
• Long term goal
• Meta language for Zephyr linking or templating system

Actions

• Clean-up offset.h to make it easier to support more compilers
• Exploration work on CI Toolchian test cases: Wayne
• Everyone: Give feedback on PR#22688, and issue: #5517: Status ?

Best regards

Torsten Tejlmand Rasmussen

Hi Carles,

I was assuming it was aimed at both of us, I’m not sure about what hardware they’re using. I’ll give it a try tomorrow with the hardware I have and see if it’s working with the latest branch of zephyr.

Thanks,

Jamie

Hi Jamie,

I think those questions were directed to Mayank, who is experiencing the issue now.

Thanks,

Carles

Hi All,

For today’s meeting let’s follow up on last meeting action items and get a status update.

Also I think we should consider the short / long term goals of this WG and who has the skills / capacity to do what.

Where:
https://zoom.us/j/967549258

Agenda

• Action items from last meeting:
• Wayne: PR22668: Continue work, and use as base for better toolchain abstraction: Status ?
• Thomas: IAR: Get basic hello world compiling, (linking with GCC) : Status ?
• Everyone: Give feedback on PR#22688, and issue: #5517: Status ?
• Toolchain WG Goals
  
  

Also some feedback has been given by Marc since last meeting:

• More reliable than code reviews, I found that gcc/clang -std=cXX -pedantic seem to work great for standard compliance. In our internal project I configured an extra build configuration with -pedantic on the side, we use it like "checkpatch" and others.

Note: Should be coupled with only checking new / modified files in a PR.

Feel free to send a mail, if you would like additional topics to be discussed.

Best regards

Torsten T. Rasmussen           

Live meeting minutes: https://docs.google.com/document/d/1IQKBK-GcJNZG0O9QArqYfvb6Huk5xHscN-XIGEZr-z8/edit#heading=h.x36xe8bnwr9r

Hi Vinayak,

> Are you using any host debugger firmware to convert to USB? or using 3v TTL connections to your custom board from nRF52840?

When I tested it, it was using an nRF52840 PCA10059-like board without a 32KHz crystal (RC was selected from zephyr), I also tried on a BL654 DVK with the 32KHz connected and set in zephyr

> For those using USB_UART conversion, I am assuming you are using Segger JLink firmware on the host chip in the nRF52840 DK/dongle. Could you try using the MBED firmware on the host debugger chip?

When I was testing the UART one, I used an FTDI chip so this does not apply. I tested against a BT850 module, which also uses an FTDI with a non-zephyr based HCI module and that worked flawlessly

> Also, please create or refer me to GH issue, so that further discussions can be continued there.

I never created an issue. I haven’t tested in probably about a year now or so.
Thanks,

Jamie

Hi Mayank,

Are you using any host debugger firmware to convert to USB? or using 3v TTL connections to your custom board from nRF52840?

For those using USB_UART conversion, I am assuming you are using Segger JLink firmware on the host chip in the nRF52840 DK/dongle. Could you try using the MBED firmware on the host debugger chip?

Also, please create or refer me to GH issue, so that further discussions can be continued there.

Regards,

Vinayak

Hi,

I’ve previously done testing with the HCI UART and USB sample apps (in older Zephyr versions) with an nRF52840 and linux PC and always found it to not work well. It would start fine, could scan for devices from bluetoothctl and then it just seemed to screw up every time with command timeouts. Never did much digging into why.

Thanks,

Jamie

> Hi All,

>

> I'm facing issues regarding ble's hci interface.

> I'm having nrf52840 module on which i run zephyr's hci_uart app for beacon scanning.

> I have Bluez 5.50 installed on my custom board (imx6ull).

>

> hci0 interface on my device is "UP RUNNING". So, i'm able to scan the beacons. (My application scans beacons after every 10 seconds).

>

> Now, When i have put my device for over night testing, then i have observed that after few hours beacon scanning was stopped.

> And i'm getting "Bluetooth: hci0 command 0x200b tx timeout" prints after every 5-10 seconds on the console, still the hci0 interface status is "UP RUNNING", but not able to scan the beacons.

>

> Sometimes also getting the prints like "Bluetooth: hci0: Frame reassembly failed (-84)".

>

> What could be the reason behind this ?

>

> Thanks,

> Mayank

Hi All,

I would like to inform you of a suggested improvement on how Zephyr is used in an application and how to source boilerplate.cmake code.

https://github.com/zephyrproject-rtos/zephyr/pull/23054

Today, each application contains:
include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)

My proposal is to create a Zephyr CMake config package, which allows a user to simply write:

find_package(Zephyr)

in the future.

But let me describe some reason for suggesting this change.

The existing solution works, and for Linux users, it is very common to use environment variables.

However, this solution also have some drawbacks.

One drawback, is that developers working both up-/ and downstream may not be able to always has a single ZEPHYR_BASE, and thus they must still remember to source zephyr-env.sh or run zephyr-env.cmd before working.

Second drawback is people using IDEs such as Eclipse or SES, must ensure that ZEPHYR_BASE is correctly set BEFORE launching the IDE.

If only having one Zephyr, that is not a big issue, but having out-of-tree applications depending on different Zephyr versions or working both up- / downstream does make this a bit more annoying.

Especially many Windows users are not fond of running a command script prior to launching their IDE.

Third drawback, is the fact that ZEPHYR_BASE is not sticky after first CMake invocation, as example, if you try the following:

$ source /tmp/zephyr-1/zephyr/zephyr-env.sh

$ cd <path-to-sample>/hello_world

$ mkdir build; cd build

$ cmake -GNinja -DBOARD=nrf52840_pca10056 ..

-- Zephyr version: 2.2.0-rc2

-- Found PythonInterp: /usr/bin/python3.6 (found suitable version "3.6.8", minimum required is "3.6")

…

Loaded configuration '/tmp/zephyr-1/zephyr/boards/arm/nrf52840_pca10056/nrf52840_pca10056_defconfig'

…

-- Build files have been written to: /tmp/zephyr-1/zephyr/samples/hello_world/build

$ ninja

…

[122/122] Linking C executable zephyr/zephyr.elf

# This could be similar to a user changing folder to do something else,

# or working in an IDE where the ZEPHYR_BASE is different from the value on first CMake invocation.

# and therefore has sourced a different Zephyr

$ source /tmp/zephyr-2/zephyr/zephyr-env.sh

# Indicate a CMakeLists.txt change causing CMake re-run on next ninja invocation.

$ touch ../CMakeLists.txt

$ ninja

[0/1] Re-running CMake...

-- Zephyr version: 2.1.99

-- Selected BOARD nrf52840_pca10056

-- Found west: /home/<user>/.local/bin/west (found suitable version "0.7.0", minimum required is "0.6.0")

-- Loading /tmp/zephyr-1/zephyr/boards/arm/nrf52840_pca10056/nrf52840_pca10056.dts as base

Error: nrf52840_pca10056.dts.pre.tmp:394.23-24 syntax error

FATAL ERROR: Unable to parse input tree

CMake Error at /tmp/zephyr-2/zephyr/cmake/dts.cmake:188 (message):

  command failed with return code: 1

Call Stack (most recent call first):

  /tmp/zephyr-2/zephyr/cmake/app/boilerplate.cmake:460 (include)

  CMakeLists.txt:5 (include)

-- Configuring incomplete, errors occurred!

See also "/tmp/zephyr-1/zephyr/samples/hello_world/build/CMakeFiles/CMakeOutput.log".

See also "/tmp/zephyr-1/zephyr/samples/hello_world/build/CMakeFiles/CMakeError.log".

FAILED: build.ninja

/opt/cmake-3.14.4-Linux-x86_64/bin/cmake -S/tmp/zephyr-1/zephyr/samples/hello_world -B/tmp/zephyr-1/zephyr/samples/hello_world/build

ninja: error: rebuilding 'build.ninja': subcommand failed

$

As seen above, the Zephyr in used is now in mixed state and thus failing.

I have therefore made the following PR, which solve both above mentioned problems, as well as give a better user experience.

https://github.com/zephyrproject-rtos/zephyr/pull/23054

It has the following advantages:

1. CMake will use `find_package` to locate the right Zephyr
2. Version can be used in an application to ensure the correct Zephyr version for Zephyr users when having multiple Out-of-tree apps
3. ZEPHYR_BASE is sticky after first CMake invocation, thus if Zephyr based is changed after first run, it will not impact subsequent CMake invocations (directly or through ninja).
4. Allows to have multiple projects with different Zephyr bases in same IDE, as example Eclipse.
5. Easier getting started for developers. No boilerplate sourcing, no ZEPHYR_BASE / zephyr-env.sh sourcing, just put:
6. Fully backward compatible with existing ZEPHYR_BASE.

So a Zephyr sample such as Hello World may look as:

https://github.com/zephyrproject-rtos/zephyr/blob/a886b9ae428c066bad73cc509757571b70a52d1f/samples/hello_world/CMakeLists.txt
# SPDX-License-Identifier: Apache-2.0

cmake_minimum_required(VERSION 3.13.1)

find_package(Zephyr 2.2.0 HINTS $ENV{ZEPHYR_BASE})

project(hello_world)

target_sources(app PRIVATE src/main.c)

And a downstream user creating an app based upon Zephyr without version check, can simply do:

`find_package(Zephyr)`

If a user wants to support the possibility of overriding the Zephyr by manually specifying ZEPHYR_BASE, the following can be used:  

`find_package(Zephyr HINTS $ENV{ZEPHYR_BASE})`

A user requiring Zephyr version 2.2.0 or above can do:

`find_package(Zephyr 2.2.0)`

A user requiring an exact Zephyr version 2.2.0 can do:

`find_package(Zephyr 2.2.0 EXACT)`

To show that Zephyr base is now sticky, I have re-tried above failure using the new principle:

$ source /tmp/zephyr-1/zephyr/zephyr-env.sh

$ mkdir build; cd build

$ cmake -GNinja -DBOARD=nrf52840_pca10056 ..

Including boilerplate (zephyr base): /tmp/zephyr-1/zephyr/cmake/app/boilerplate.cmake

-- Zephyr version: 2.2.0-rc2

-- Found PythonInterp: /usr/bin/python3.6 (found suitable version "3.6.8", minimum required is "3.6")

…

Loaded configuration '/tmp/zephyr-1/zephyr/boards/arm/nrf52840_pca10056/nrf52840_pca10056_defconfig'

…

-- Build files have been written to: /tmp/zephyr-1/zephyr/samples/hello_world/build

$ ninja

…

[119/124] Linking C executable zephyr/zephyr_prebuilt.elf

Memory region         Used Size  Region Size  %age Used

           FLASH:       11484 B         1 MB      1.10%

            SRAM:        5180 B       256 KB      1.98%

        IDT_LIST:          56 B         2 KB      2.73%

[124/124] Linking C executable zephyr/zephyr.elf

$ source /tmp/zephyr-2/zephyr/zephyr-env.sh

$ touch ../CMakeLists.txt

$ ninja

[0/1] Re-running CMake...

Including boilerplate (zephyr base (cached)): /tmp/zephyr-1/zephyr/cmake/app/boilerplate.cmake

-- Zephyr version: 2.2.0-rc2

…

-- Loading /tmp/zephyr-1/zephyr/boards/arm/nrf52840_pca10056/nrf52840_pca10056.dts as base

…

Loaded configuration '/tmp/zephyr-1/zephyr/samples/hello_world/build/zephyr/.config'

No change to configuration in '/tmp/zephyr-1/zephyr/samples/hello_world/build/zephyr/.config'

No change to Kconfig header in '/tmp/zephyr-1/zephyr/samples/hello_world/build/zephyr/include/generated/autoconf.h'

…

-- Build files have been written to: /tmp/zephyr-1/zephyr/samples/hello_world/build

[86/90] Linking C executable zephyr/zephyr_prebuilt.elf

…

[90/90] Linking C executable zephyr/zephyr.elf

$ echo $ZEPHYR_BASE

/tmp/zephyr-2/zephyr

Also a small screenshot from Eclipse to show that two projects can be imported with different Zephyr bases, and both be built and using their own Zephyr base (and in  this example own requested Zephyr version):

If anyone is interested in a presentation of the new possibilities, I will be happy to make a small presentation for next TSC meeting.

Torsten Tejlmand Rasmussen

Senior R&D Engineer

P: +47 72 89 92 47

Nordic Semiconductor

Otto Nielsens veg 12, 7052 Trondheim, Norway

www.nordicsemi.com