How to get Chrome Web Bluetooth working on Linux

In my previous post I demonstrated how to test and scan for Bluetooth Low Energy:
https://acassis.wordpress.com/2016/06/27/getting-started-with-bluetooth-low-energy-on-linux/

Now I will explain what I did to get Bluetooth Low Energy working on Linux Debian.

First I installed the Chrome Dev version 53 from here:
https://www.google.com/chrome/browser/desktop/index.html?platform=linux&extra=devchannel

But the Bluetooth Scan Page example was not working:
https://googlechrome.github.io/samples/web-bluetooth/device-info.html

Then searching in the forums I discovered these four requirements to get it working:
1) A recente Chrome version 45+ (I’m using version 53);
2) A recente Linux kernel 3.19+ (my kernel was too old: 3.16);
3) BlueZ 5.40+ (my bluez version was 5.36);
4) Bluetooth daemon (bluetoothd) running with experimental interface (/usr/bin/bluetoothd -E).

Then I updated my Linux kernel:

$ sudo apt-get install linux-image-4.6.0-1-amd64

Compiled Bluez 5.40:

// Install the dependecies:
$ sudo apt-get -y install automake autotools-dev bison check clang flex lcov libcap-ng-dev libdbus-glib-1-dev libdw-dev libglib2.0-dev libical-dev libreadline-dev libtool libudev-dev

//Download bluez-5.40:
$ wget http://www.kernel.org/pub/linux/bluetooth/bluez-5.40.tar.xz

//Extract it:
$ tar xvf bluez-5.40.tar.xz

// Configure and compile it:
$ cd bluez-5.40
$ ./configure --prefix=/usr           \
            --mandir=/usr/share/man \
            --sysconfdir=/etc       \
            --localstatedir=/var    \
            --enable-library        \
            --disable-systemd       \
            --disable-android       \
            --enable-experimental
$ make

// Create a debian package with checkinstall:
$ sudo checkinstall

Here checkinstall didn’t create the /usb/bin/bluetoothd link, let us to create it:

# ln -s /usr/libexec/bluetooth/bluetoothd /usr/bin/bluetoothd

We need to stop bluetoothd daemon and call it with -E:

# /etc/init.d/bluetooth stop
# /usr/libexec/bluetooth/bluetoothd -E &

Now let see if Chromium could communicate with the BLE device:

$ ./chrome --enable-web-bluetooth

Then open the sample page to test Discover Services and Characteristics:
https://googlechrome.github.io/samples/web-bluetooth/discover-services-and-characteristics.html

I will test the Nordic Serial Service, then I enter:

6e400001-b5a3-f393-e0a9-e50e24dcca9e

After updating bluez to version 5.40 the Bluetooth Chooser pop-up window stopped to list the nearby Bluetooth LE devices.

This issue was caused because I used “ControllerMode = le” in the /etc/bluetooth/main.conf. This BUG didn’t exist in the bluez 5.36.

Changing “ControllerMode = dual” in the /etc/bluetooth/main.conf fixed the issue (thanks François Beaufort for the help).

And after restarting bluetoothd and clicking on “Discover services and characteristics” and choosing the Nordic_UART device, it returns:

Requesting any Bluetooth Device...
> Name:             Nordic_UART
> Allowed Services: 6e400001-b5a3-f393-e0a9-e50e24dcca9e
Connecting to GATT Server...
Getting Services...
Getting Characteristics...
> Service: 6e400001-b5a3-f393-e0a9-e50e24dcca9e
>> Characteristic: 6e400003-b5a3-f393-e0a9-e50e24dcca9e [NOTIFY]
>> Characteristic: 6e400002-b5a3-f393-e0a9-e50e24dcca9e [WRITEWITHOUTRESPONSE, WRITE]

References:
https://github.com/beaufortfrancois/sandbox/blob/gh-pages/web-bluetooth/Bluez.md
http://www.linuxfromscratch.org/blfs/view/svn/general/bluez.html

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