Demo controlling the fischertechnik BT smart controller from within a browser via Web Bluetooth and/or Web USB.
To run this demo open the following link using google chrome:
https://technika-karlsruhe.github.io/bt_smart_web/
This demo has been tested under Windows, Linux, MacOS and Android.
The Web Bluetooth part should work on Windows out of the box. Web USB may need some help. If the attempt to use Web USB ends with a "Access Denied" error, the WinUSB driver may not ba assigned to the BT Smart Controller. The Zadig tool will probably be able to solve this. Use the tool to search for the "BT Smart Controller" use it to replace the exiting driver with WinUSB driver. Afterwards the Web USB part should work as well.
The original driver and the COM port are not associated with the board afterwards. Re-installing the driver in the system settings will restore the original default driver and restore the COM port.
Under Ubuntu Linux the Chrome/Chromium is by default installed from a snap archive and is by default sandboxed. It thus doesn't have the necessary permissions to access USB. The following command allows for raw USB access from within Chrome/Chromium:
sudo snap connect chromium:raw-usb
Furthermore direct USB permissions may need to be given to the current user. Creating a file named /etc/udev/rules.d/99-btsmart.rules containing the following line will give the necessary permissions.
ATTRS{idVendor}=="221d" ATTRS{idProduct}=="0005", MODE="664", GROUP="plugdev"
Web Bluetooth as well as Web USB version works out of the box on Chrome on MacOS.
The demo runs out of the box with the chrome preinstalled on any recent android device. However, for the USB version to work a so-called "USB to mini USB host mode cable" or "USB on-the-go (OTG) to mini USB adapter" is needed. This cable should have a connector matching your Android device on one side (e.g. USB-C on recent phones) and a Mini-USB connector on the other side matching the BT Smart controller.
