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Multi-User Access

Prefer slides? View the Multi-User Access Slides for a visual walkthrough.

Multiple students can access the same Pi simultaneously for collaborative work.

Important: One Camera = One Person Running the Script

Key concept: Each Pi has ONE camera. Only ONE person should run person_detector.py at a time.

Smart object feature: When you run the script with --discord, the camera automatically announces who's using it!

Typical Classroom Workflow

# Student A runs the script:
ssh orbit
source /opt/oak-shared/venv/bin/activate
python3 person_detector.py --discord

# Discord automatically shows:
# 🎥 **alice** is now running person_detector.py on **orbit**

# Other students can simultaneously:
# - SSH in and view/edit code via VS Code Remote
# - Make their own copies: person_detector_bob.py
# - Prepare changes for when it's their turn
# - Watch the Discord channel to see who's using which camera

# When Student A stops (Ctrl+C):
# Discord automatically shows:
# 📴 **alice** stopped person_detector.py on **orbit** - camera is free

No manual coordination needed! The camera announces itself automatically.

Best Practices for Shared Access

1. Check Discord Before Running

  • The camera automatically announces who's using it
  • If no "camera is free" message recently, check: ps aux | grep person_detector.py
  • Be considerate: Don't run for hours - test and let others use it
  • Run with --discord flag so others can see when you're done

2. Everyone Can Collaborate via Code Editing

  • Multiple people can SSH in simultaneously to view/edit code
  • Use VS Code Remote SSH - each person gets their own editing session
  • Create personal test scripts: 
    cd ~/oak-projects
cp person_detector.py person_detector_alice.py
cp person_detector.py person_detector_bob.py
# Edit your copy, test when camera is free

3. Use Git for Collaboration

  • Work on your own branch: git checkout -b feature/alice-zone-detection
  • Commit changes when you've tested them
  • See GIT_COLLABORATION.md for strategies

4. Communication is Essential

  • Let teammates know before you run the detector
  • Don't stop someone else's running script
  • Use a shared Discord/Slack channel to coordinate
  • If unsure, ask: "Is anyone using Camera 1?"

Adding Your SSH Key

If multiple people use the same Pi account, each person can add their own SSH key for passwordless access.

On Mac/Linux:

# Generate key if you don't have one (with project-specific name)
ssh-keygen -t ed25519 -f ~/.ssh/id_ed25519_smartobjects -C "your_email@example.com"

# Copy to Pi (if SSH config is set up from Part 1)
ssh-copy-id orbit

# Or specify the key explicitly
ssh-copy-id -i ~/.ssh/id_ed25519_smartobjects.pub orbit

On Windows (PowerShell):

# Generate key if needed (with project-specific name)
ssh-keygen -t ed25519 -f $env:USERPROFILE\.ssh\id_ed25519_smartobjects -C "your_email@example.com"

# Copy to Pi manually
type $env:USERPROFILE\.ssh\id_ed25519_smartobjects.pub | ssh orbit "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

Multiple Keys for Shared Account

Each person's key gets added to the same authorized_keys file:

# Person 1 adds their key
ssh-copy-id orbit

# Person 2 adds their key (doesn't overwrite Person 1's key)
ssh-copy-id orbit

# Or manually add keys
ssh orbit
nano ~/.ssh/authorized_keys
# Paste each person's public key on a new line

Now everyone can connect without a password!

Adding Additional User Accounts (Optional)

If you want separate user accounts for each student:

# SSH into the Pi
ssh orbit

# Create new user
sudo adduser alice

# Add to required groups for camera access
sudo usermod -aG video,gpio,i2c,spi alice

# Copy project files to their home directory
sudo cp -r /home/pi/oak-projects /home/alice/
sudo chown -R alice:alice /home/alice/oak-projects

# The new user can now log in (update SSH config with new username)
ssh orbit  # (after updating SSH config User field)

Shared Resources (Already Configured)

The following shared resources have already been set up on all three Pis:

Shared Model Cache

  • Location: /opt/depthai-cache
  • What it does: DepthAI models download once and are accessible to all users
  • Why it matters: Prevents permission errors when multiple students test their own script copies
  • No action needed - this is already configured!

Shared Oak Examples

  • Location: /opt/oak-shared/oak-examples/
  • Symlink: ~/oak-examples/ in each user's home directory
  • What it includes: Luxonis example code for neural networks, depth, tutorials, etc.
  • Browse examples whenever you want inspiration for new features!

For setup details (instructors only), see docs/archive/multi-user-setup.md

Related Documentation