MBot Bridge

Server and API to bridge MBot functionality with student code.

Dependencies:

• Python 3 (tested on 3.10)
• LCM 1.4+ (tested on 1.5)
• MBot messages for Python and C++

See the Documentation for more details.

Install Instructions

To install the MBot Bridge, the API, and all the related services, do:

./scripts/install.sh

Warning: This globally installs the MBot Bridge API and its Python and C++ dependencies. Only do this on an MBot. In general, it's recommended to install Python packages in virtual environments instead.

Usage

For development, it is best to use a virtual environment. From your virtual environment, do:

python -m pip install -e .

To run the server, do:

python -m mbot_bridge.server [--config [PATH/TO/CONFIG]]

The --config argument is optional and will default to src/mbot_bridge/config/default.yml.

Do python -m mbot_bridge.server -h for a full list of options.

Import errors in your virtual environment? If you get import errors (e.g. for NumPy and LCM) you need to share the system packages with the virtual environment. If you are using venv, you can do this with:

python3 -m venv --system-site-packages ~/.envs/my-mbot-env

Alternatively, set your PYTHONPATH variable to tell your Python interpreter to check the global path for libraries:

export PYTHONPATH=$PYTHONPATH:/usr/lib/python3/dist-packages/:/usr/local/lib/python3.X/dist-packages/

Make sure you replace python3.X with your installed Python version.

C++ API

To use the C++ API, first install the websocket library at the latest release version:

wget https://github.com/zaphoyd/websocketpp/archive/refs/tags/0.8.2.tar.gz
tar -xzf 0.8.2.tar.gz
cd websocketpp-0.8.2/
mkdir build && cd build
cmake ..
make
sudo make install

Then, compile the C++ API:

cd mbot_bridge
mkdir build
cd build
cmake ../mbot_cpp/
make

To install the C++ API globally, do:

sudo make install

A test script is available at:

./build/mbot_cpp_test

JavaScript API

The JavaScript API can be installed using NPM as follows:

cd mbot_js
npm install
npm run build

Then include the bundled script mbot_js/dist/main.js where you want to use the API. To create a MBot object, do:

const mbot = new MBotAPI.MBot(mbotIP);

where mbotIP is the IP address of the mbot.

Usage

To test the JS API, a test script is available in the test directory. To use it, start an HTTP server in the root of this repo:

python -m http.server

Then navigate to http://[HOST_IP]:8000/test in a browser. If running locally, use the IP localhost.