multicast/broadcast support

Example/README.md

@@ -31,9 +31,19 @@ For the example commands to work, create a simple test scene:
 
 The example includes these simple commands:
 
+### Standard Commands (Single IP)
 - **Toggle Cube**: Enables/Disables the TestCube GameObject
 - **Start Timer**: Starts a 10-second countdown timer
 - **Reset Scene**: Reloads the current scene
+- **Rotate Cube**: Rotates the cube at different speeds
+- **Change Color**: Changes the cube color (red, blue, green)
+
+### Broadcast Commands
+- **Broadcast: Toggle All Cubes**: Sends the toggle command to all Unity instances on your network
+- **Broadcast: Reset All Scenes**: Resets scenes on all Unity instances on your network
+
+### Multi-IP Commands
+- **Multi-IP: Start Timers**: Sends the start timer command to multiple specific IP addresses simultaneously
 
 ## UDP Protocol
 
@@ -55,9 +65,35 @@ You can add your own commands by:
 1. Adding a new case in the `ProcessCommand` method in `UDPCommandListener.cs`
 2. Creating a corresponding JSON entry in your project file
 
+## Broadcast Mode
+
+Broadcast mode allows you to send UDP packets to all devices on your local network simultaneously. This is useful when you have multiple Unity instances running on different computers.
+
+### How to Use Broadcast
+1. In the UnityUDP app, create or edit a package
+2. Enable the "Broadcast Mode" toggle
+3. Send the package - it will reach all Unity instances listening on the specified port
+
+### Network Requirements
+- All devices must be on the same local network
+- Firewall must allow UDP broadcast traffic
+- Unity instances must be listening on the same port
+
+## Multiple IP Addresses
+
+You can send the same command to multiple specific IP addresses at once:
+
+1. In the UnityUDP app, create or edit a package
+2. Add multiple IP addresses using the "Add IP" button
+3. All added IPs will receive the packet when you send
+
+This is useful for targeting specific Unity instances without broadcasting to the entire network.
+
 ## Troubleshooting
 
 - **Commands not working**: Check that your firewall allows UDP traffic on the specified port
 - **Can't connect**: Verify the IP address is correct (use `ipconfig` on Windows or `ifconfig` on Mac/Linux)
 - **Unity crashes**: Make sure all GameObject names match the ones in the script
+- **Broadcast not working**: Ensure your firewall allows UDP broadcast (255.255.255.255) and all devices are on the same subnet
+- **Multi-IP partial failure**: Check network connectivity to each IP address individually