Phase 4: Device Discovery Framework

[tylerkron]

Phase 4: Device Discovery Framework

This issue tracks Phase 4 from the migration plan: moving device discovery logic from daqifi-desktop to daqifi-core.

Success Criteria

4.1 Device Discovery Interfaces

• Create IDeviceFinder interface for device discovery
• Create IDeviceInfo interface/class for discovered device metadata
• Support for multiple discovery mechanisms (WiFi, Serial, USB HID)
• Async discovery with cancellation token support
• Event-based discovery notifications (device found, discovery complete)

4.2 WiFi Device Discovery

• Implement WiFiDeviceFinder using UDP broadcast
• UDP broadcast on port 30303 with "DAQiFi?\r\n" query
• Parse protobuf responses containing device info (IP, MAC, port, hostname, serial, firmware version)
• Support for custom broadcast messages
• Network interface enumeration and selection
• Timeout and retry configuration

4.3 Serial Device Discovery

• Implement SerialDeviceFinder for USB/Serial enumeration
• Serial port scanning with device info queries
• TryGetDeviceInfo() pattern with quick connection attempts
• Configurable baud rates and DTR control
• Device identification from serial responses

4.4 USB HID Device Discovery (for firmware updates)

• Implement HidDeviceFinder for bootloader mode devices
• HID device enumeration (VendorId: 0x4D8, ProductId: 0x03C)
• Device mode detection (normal vs bootloader)

4.5 Device Info Extraction

• Parse device metadata from protobuf messages
• Extract IP address, MAC address, TCP port
• Device hostname, serial number, firmware version
• Device type detection from part numbers
• Power status information

Implementation Guidance

Discovery Interface Example

public interface IDeviceFinder
{
    event EventHandler<DeviceDiscoveredEventArgs>? DeviceDiscovered;
    event EventHandler? DiscoveryCompleted;
    
    Task<IEnumerable<IDeviceInfo>> DiscoverAsync(CancellationToken cancellationToken = default);
    Task<IEnumerable<IDeviceInfo>> DiscoverAsync(TimeSpan timeout);
}

public interface IDeviceInfo
{
    string Name { get; }
    string SerialNumber { get; }
    string FirmwareVersion { get; }
    IPAddress? IPAddress { get; }
    string? MacAddress { get; }
    int? Port { get; }
    DeviceType Type { get; }
}

WiFi Discovery Example

// Core should support WiFi discovery
var finder = new WiFiDeviceFinder();
finder.DeviceDiscovered += (s, e) => Console.WriteLine($"Found: {e.DeviceInfo.Name}");

var devices = await finder.DiscoverAsync(TimeSpan.FromSeconds(5));
foreach (var device in devices)
{
    Console.WriteLine($"{device.Name} at {device.IPAddress}:{device.Port}");
}

Serial Discovery Example

// Core should support serial enumeration
var finder = new SerialDeviceFinder();
finder.BaudRate = 115200;
finder.EnableDtr = true;

var devices = await finder.DiscoverAsync();
foreach (var device in devices)
{
    Console.WriteLine($"{device.Name} on {device.PortName}");
}

Desktop Migration Impact

Once complete, desktop can migrate:

• DaqifiDeviceFinder → use WiFiDeviceFinder from core
• SerialDeviceFinder → use core implementation
• HidDeviceFinder → use core implementation
• Device enumeration logic → removed from desktop

Testing Requirements

• Unit tests for each finder type
• Mock network/serial responses for testing
• Discovery timeout tests
• Multiple device discovery tests
• Cancellation token tests
• Platform-specific discovery tests
• Integration tests with real devices (manual/optional)

Target Version

Core 0.6.0

Dependencies

• Depends on: Phase 3 (Connection Management - UDP transport needed)
• Blocks: Phase 5 (Channel Management)

Related Documentation

Desktop implementation references:

• /Device/WiFiDevice/DaqifiDeviceFinder.cs - UDP discovery on port 30303
• /Device/SerialDevice/SerialDeviceFinder.cs - Serial port scanning
• /Device/HidDevice/HidDeviceFinder.cs - HID enumeration