ot2_workcell

The ot2_workcell repo consists of a collection of ROS2 packages which work in tandem to operate the Opentrons OT2-based liquid handling operations of Argonne National Laboratory's Rapid Prototyping Lab (ANL RPL). This so far includes a workcell manager, OT2 controller, plate-handling robotic arm controller, each of the previous component's respective clients, and a set of common interfaces, with the ability to add new components on an as-needed basis.

This workcell will eventually support:

• Dynamic, dependency-driven and task-based resource scheduling
• Resource reservations
• Intelligent error handling and recovery
• Closed-loop AI experimentation and "Autonomous Discovery" functionality

Development

Install ROS2 Foxy

• On Ubuntu, Mac, or Windows
• On a Raspberry Pi 4

Install the Packages

This is assuming an Ubuntu 20.04 environment with ROS Foxy installed.

1. cd ~
2. source /opt/ros/foxy/setup.bash
3. mkdir -p ~/ot2_ws/src
4. cd ~/ot2_ws/src
5. git clone https://github.com/AD-SDL/ot2_workcell.git
6. cd ot2_workcell && git clone https://github.com/AD-SDL/ot2_driver.git && git clone https://github.com/AD-SDL/pf400_driver.git && git clone https://github.com/AD-SDL/workcell_manager.git Bring in OT2 driver / PF400 driver / Scheduler Driver
7. cd ~/ot2_ws
8. rosdep update && rosdep install -i --from-path src --rosdistro foxy -y
9. sudo apt install python3-colcon-common-extensions
10. colcon build
11. source install/setup.bash

Database Setup

1. Note No need to do this anymore, modify the launch files. In ot2_driver_pkg/protocol_handler/protocol_handling_client.py in the functionsend_message_to_OT2(...) sock.connect(...) needs to be changed to your IP and whatever port you want
2. To Install Mysql Database Server.

• Note: Installation process is included for testing purposes with the local setups. Eventually, Mysql server will be runnnig on the servers located in Argonne National Laboratory and this process will not be necessary.
• sudo apt-get update && sudo apt-get upgrade
• sudo apt install mysql-server
• mysql --version ->> Check if the installation was successful

3. Configure Mysql Server for Remote Connections

• sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf ->> Edit "bind-address = 127.0.0.1". Use "0.0.0.0" for all remote connections (not suggested for security reasons) or use the IP address of the machine that will be used for remote connections
• sudo systemctl restart mysql
• sudo mysql -u root ->> Log in to MySQL Server
• CREATE USER 'username'@'remote_server_ip' IDENTIFIED BY 'password';
• GRANT CREATE, ALTER, DROP, INSERT, UPDATE, DELETE, SELECT, REFERENCES, RELOAD on *.* TO 'username'@'remote_server_ip' WITH GRANT OPTION;
• FLUSH PRIVILEGES;

4. Create a config.py in the home directory and include the below lines

• #Database variables
• DBNAME = "DATABASENAME"
• DBUSER = "USERNAME"
• DBPASSWD = "USERPASSWORD"
• DBHOST = "HOST_NAME or HOST_IP_ADDRESS"

5. For testing on the actual OT2! In ot2_driver_pkg/protocol_handler/protocol_parser.py in the function protocol_parser(...) the commented line new_file.write("import error_handling\n") needs to be uncommented
6. Note this step no longer needs to be done. In ot2_driver_pkg/protocol_handler/protocol_transfer.py in the function transfer(...) the host_ip and user need to be changed to match the database you have
7. Protocols need to be added to the /data folder, to change this in ot2_driver_pkg/protocol_handler/protocol_transfer.py in the function transfer(...) the line scp.put(local_path, recursive=True, remote_path='/tmp') the remote path /tmp needs to be changed to /data. You also need to change in ot2_driver_pkg/protocol_handler/protocol_handling_client.py in the function handler(...) the line msg_error, msg_output, msg_errorcode = send_message_to_OT2("python3 "+ "/tmp/" + protocol.split("/")[-1]) the /tmp/ needs to be changed to /data

Launching OT2_workcell

Workcell Manager

1. source ~/ot2_ws/install/setup.bash
2. ros2 run ot2_workcell_manager master

Arm

1. source ~/ot2_ws/install/setup.bash
2. ros2 launch arm_controller arm_bringup.launch.py

Opentrons OT-2 bob

1. source ~/ot2_ws/install/setup.bash
2. ros2 launch ot2_controller ot2_bob_bringup.launch.py

Opentrons OT-2 alex

1. source ~/ot2_ws/install/setup.bash
2. ros2 launch ot2_controller ot2_alex_bringup.launch.py

Scheduler Manager

1. source ~/ot2_ws/install/setup.bash
2. ros2 run scheduler_controller scheduler_manager

Scheduler Work Adder

1. source ~/ot2_ws/install/setup.bash
2. ros2 run scheduler_controller scheduler_work_adder

OT2 Client
This is for each OT2 that you plan on recieving jobs on and must be run on the OT2.

1. ssh -i ot2_ssh_key root@10.140.54.14
2. cd
3. python3 OT2_listener.py

Note: Create a new ssh key for each OT2 and use their IP addresses. Known OT2 IP addresses: 10.140.54.14 | 10.140.54.15

If you would like to run the OT2_listener.py in your local for testing purposes only

1. source ~/ot2_ws/install/setup.bash
2. python3 ~/ot2_ws/src/ot2_workcell/ot2_driver_pkg/zeroMQ_OT2/OT2_listener.py

TODO: Write a bashrc script in each of the OT2s and RPIs to automatically launch the listeners when they are powered on.

This will cause nodes to be registered with master and you can insert workflow files via the Scheduler Work Adder which will prompt you for workflow files. It will automatically schedule that workflow to available OT2s.

Test Bench for Deadlock Detection

1. source ~/ot2_ws/install/setup.bash
2. python3 ~/ot2_ws/src/ot2_workcell/scheduler_client/scheduler_client/test_bench.py

This will run all of the deadlock detection tests.

Testing for Reading Workflow Files

1. source ~/ot2_ws/install/setup.bash
2. ros2 run scheduler_client json_scheduler_reader

This will read the workflow.json file in the OT2_modules directory and print it to the screen

Workflow file format

Workflow files are json files and must be formatted as such. The first section is the blocks section. You specify a list of blocks each block has the following information,

1. block-name, the unique name of the block, the scheduler showed throw an error if there are duplicate names
2. tasks, a string with all the different task that need to be run separated by spaces
3. dependencies, a string with all the dependencies off that block that are separated by spaces

Format

'blocks': [ 	{'block-name':'[Your Block Name]', 'tasks':'[protocol1 protocol2 protocol3 ...]', 'dependencies':'[block_name_1 block_name_2 ...]'},
		{'block-name':'[Your Block Name]', 'tasks':'[protocol1 protocol2 protocol3 ...]', 'dependencies':'[block_name_1 block_name_2 ...]'},
		{'block-name':'[Your Block Name]', 'tasks':'[protocol1 protocol2 protocol3 ...]', 'dependencies':'[block_name_1 block_name_2 ...]'},
		{...}
	   ]

After the blocks section you have the meta-data (dictionary) section which contains

1. author, the creator of the workflow file
2. email, the email of the creator
3. description, describes what the workflow file does

Format

"meta-data": {
		"author": "[Author Name]",
		"email": "[Author Email]", 
		"description": "[Description of the Workflow File]"
	     }    

Example workflow file is in the OT2_Modules/workflow.json.

Diagrams for different components

Useful Commands

• colcon graph --dot | dot -Tpng -o deps.png Generates a dependency graph image for the packages