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Connect any ROS-compatitable robot under Robonomics parachain control. Part 2: IPFS

In this article we will continue using Robonomics tools to make a drone be controlled by a parachain. This time we will add sending data to IPFS and hash storing in chain options. Below is the instruction and code snippets. Requirements:

  • Part 1 of this tutorial
  • Ubuntu 18.04 LTS
  • ROS Melodic + Gazebo + RViz (installation manual here)
  • IPFS 0.4.22 (download from here and install)
  • Robonomics node (binary file) (download latest release here)
  • Python dependencies:
pip install cv_bridge ipfshttpclient

1. Add dependencies

If we launch a simulation and look at the topic list (see previous tutorial), we will see, that there is one topic containing front camera data and using sensor_msgs/Image message type:

front_camera

Let's try to take a picture every 1 second and after the flight publish these photos to IPFS. If you have completed the first tutorial, you don't need to download anything else. It's the drone_sample_controller_pictures.py script.

2. Manage accounts in DAPP

As done in a previous tutorial, create a local robonomics network node with robonomics binary file:

./robonomics --dev

Important! Before next launches it is necessary to remove a directory db with

rm -rf /home/$USER/.local/share/robonomics/chains/dev/db

After a successful launch create accounts following this manual. Do not forget to save each account's seed and address! You will need them for transactions. Add these addresses, seeds and path to robonomics binary file to file config.config in robonomics_ws/src/robonomics_sample_controller/src. Transfer some money (units) to these accounts:

balances

3. Launch

Up to now the only thing running should be the robonomics local node. In a separate terminal launch drone simulation:

roslaunch sjtu_drone simple.launch

In another one launch ipfs daemon:

ifps init # you only need to do this once
ipfs daemon

Run the script:

rosrun drone_simulator_controller drone_sample_controller_pictures.py

Now you can send a transaction triggering the drone to start flying and taking pictures. To do so, you should use the Robonomics IO write subcommand of robonomics binary file:

echo "ON" | ./robonomics io write launch -r <DRONE_ADDRESS> -s <EMPLOYER’S_KEY>

Where <DRONE_ADDRESS> and <EMPLOYER’S_KEY> are replaced with previously saved strings accordingly. You should see the log "Taking Off" and the drone should start flying and taking pictures:

flying_picturing

Later, when the job is done, on the Robonomics portal go to Developer -> Chain state and add a DRONE datalog using “+” button with selected datalog as state query. The IPFS hash of the telemetry has been saved in the blockchain. To see the data simply copy the hash and add it to the local gateway address localhost:8080/ipfs/:

Voila