7.3 TCP Socket Remote Control

TCP Socket mode runs the Python client on a PC. The UNO Q service receives client commands and communicates with the robot through Bridge RPC. Install Python 3 and a pymycobot version containing MyCobot280Socket on the PC before use.

1. PC Python Environment

Windows

1. Install Python 3 from python.org and select Add Python to PATH.
2. Confirm the environment:

python --version
python -m pip --version

1. Create a virtual environment and install pymycobot:

python -m venv .venv
.venv\Scripts\activate
python -m pip install --upgrade pip
python -m pip install --upgrade pymycobot

macOS / Linux

python3 --version
python3 -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install --upgrade pymycobot

Verify the Client Class

python -c "from pymycobot import MyCobot280Socket; print('MyCobot280Socket ready')"

Do not use the board-side unoq_bridge=True initialization on the PC.

2. Check the UNO Q Service

Run these commands in the UNO Q terminal:

hostname -I
systemctl is-active mycobot-server.service
ss -lntp | grep ':9000'

The service must show active and port 9000 must listen. Select a UNO Q address on the same subnet as the PC; do not use 0.0.0.0 as a client destination.

For a service failure, view logs:

systemctl status mycobot-server.service --no-pager
journalctl -u mycobot-server.service -n 100 --no-pager

3. Check the Network

Keep the PC and UNO Q on the same trusted LAN. On Windows, test the port:

Test-NetConnection UNO_Q_IP -Port 9000

For macOS or Linux, use an available network utility to check UNO_Q_IP:9000. If it is unreachable, resolve the IP address, network isolation, firewall, or UNO Q service state first.

4. Connect from the PC Client

Replace UNO_Q_IP with the actual UNO Q address. Save this as uno_q_socket_test.py and start with a read-only test:

from pymycobot import MyCobot280Socket

mc = MyCobot280Socket("UNO_Q_IP", 9000, debug=True)
print("version:", mc.get_system_version())
print("angles:", mc.get_angles())

Run it in the PC virtual environment:

python uno_q_socket_test.py

After successful reads, run only a confirmed-safe motion command:

mc.send_angles([0, 0, 0, 0, 0, 0], 30)

5. Usage Limits

• The service processes one client at a time; do not connect multiple control clients simultaneously.
• Exit the TCP client normally before switching to App Lab or a board-side script.
• Never expose port 9000 to the public internet.
• Use debug=True for troubleshooting and turn it off for performance measurements.
• Before restarting the service, confirm that no program is controlling the robot:

sudo systemctl restart mycobot-server.service
systemctl status mycobot-server.service --no-pager

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