Linux Ubuntu for Radio Astronomy: ACM0 Service for PicoMuon

The error message:

Unit file PicoMuonACM0.service does not exist

means that systemd can’t find a service file named PicoMuonACM0.service. To resolve this, you’ll need to create, place, or enable the service file correctly. Here’s how to go through the full process.

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🛠️ Steps to Create and Enable the Service

1. Create the Service File

Assuming this service is for a script or executable associated with your PicoMuon detector connected to /dev/ttyACM0, you can create a unit file like:

# /etc/systemd/system/PicoMuonACM0.service
[Unit]
Description=PicoMuon Service for /dev/ttyACM0
After=network.target

[Service]
ExecStart=/usr/local/bin/pico_muon_logger.sh
Restart=always
User=pi
Group=pi

[Install]
WantedBy=multi-user.target

✅ Adjust:

• ExecStart to your actual script or binary path
• User and Group to match who should run it

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2. Reload systemd to Detect the New Service

sudo systemctl daemon-reexec
sudo systemctl daemon-reload

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3. Enable and Start the Service

sudo systemctl enable PicoMuonACM0.service
sudo systemctl start PicoMuonACM0.service

Check its status:

sudo systemctl status PicoMuonACM0.service

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🧪 Debugging Tips

• If it’s a USB serial device that dynamically changes (e.g., /dev/ttyACM0 might not always be the same), consider using udevadm info -a -n /dev/ttyACM0 to find a more stable device path like /dev/serial/by-id/....
• Make sure your script can access /dev/ttyACM0 and has permission.
• Add logging to your script or the unit file with StandardOutput=journal or use journalctl -u PicoMuonACM0.service to view logs.