feat: auto-detect DJI 4G modules (#32)

internal/modem/discovery.go

@@ -11,7 +11,11 @@ import (
 	"strings"
 )
 
-const quectelVendorID = "2c7c"
+const (
+	quectelVendorID = "2c7c"
+	djiVendorID     = "2ca3"
+	dji4GProductID  = "4006"
+)
 
 type SysFSDiscoverer struct {
 	SysRoot string
@@ -70,13 +74,13 @@ func (d *SysFSDiscoverer) Discover(ctx context.Context) ([]Candidate, error) {
 			resolvedDevice = devicePath
 		}
 		vendorID := strings.ToLower(readTrimmed(filepath.Join(resolvedDevice, "idVendor")))
-		if vendorID != quectelVendorID {
+		productID := strings.ToLower(readTrimmed(filepath.Join(resolvedDevice, "idProduct")))
+		if !isSupportedUSBModem(vendorID, productID) {
 			continue
 		}
 
 		state := devices[deviceName]
 		if state == nil {
-			productID := strings.ToLower(readTrimmed(filepath.Join(resolvedDevice, "idProduct")))
 			serialNumber := readTrimmed(filepath.Join(resolvedDevice, "serial"))
 			state = &discoveredUSBDevice{
 				candidate: Candidate{
@@ -141,6 +145,19 @@ func (d *SysFSDiscoverer) Discover(ctx context.Context) ([]Candidate, error) {
 	return result, nil
 }
 
+func isSupportedUSBModem(vendorID, productID string) bool {
+	return strings.EqualFold(strings.TrimSpace(vendorID), quectelVendorID) ||
+		IsDJI4GUSB(vendorID, productID)
+}
+
+// IsDJI4GUSB reports whether a USB identity belongs to the first-generation
+// DJI/Baiwang 4G module. It keeps the factory 2ca3:4006 identity usable without
+// requiring a persistent AT+QCFG USB identity rewrite to Quectel 2c7c:0125.
+func IsDJI4GUSB(vendorID, productID string) bool {
+	return strings.EqualFold(strings.TrimSpace(vendorID), djiVendorID) &&
+		strings.EqualFold(strings.TrimSpace(productID), dji4GProductID)
+}
+
 type discoveredWWANDevice struct {
 	index    string
 	ports    []Port

internal/modem/discovery_common_test.go

@@ -2,6 +2,29 @@ package modem
 
 import "testing"
 
+func TestSupportedUSBModemIdentity(t *testing.T) {
+	tests := []struct {
+		name      string
+		vendorID  string
+		productID string
+		want      bool
+	}{
+		{name: "Quectel", vendorID: "2c7c", productID: "0125", want: true},
+		{name: "DJI 4G module", vendorID: "2ca3", productID: "4006", want: true},
+		{name: "DJI 4G module uppercase", vendorID: "2CA3", productID: "4006", want: true},
+		{name: "unrelated DJI device", vendorID: "2ca3", productID: "001f", want: false},
+		{name: "unrelated USB device", vendorID: "0403", productID: "6001", want: false},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got := isSupportedUSBModem(test.vendorID, test.productID); got != test.want {
+				t.Fatalf("isSupportedUSBModem(%q, %q) = %v, want %v", test.vendorID, test.productID, got, test.want)
+			}
+		})
+	}
+}
+
 func TestSelectATPortPrefersTTYUSB2AcrossUSBCompositions(t *testing.T) {
 	ports := []Port{
 		{Name: "ttyUSB2", InterfaceNumber: 0x02, Role: PortRoleDiagnostic},

internal/server/device_api.go

@@ -387,6 +387,7 @@ func (s *Server) handleDiscoveredDevices(w http.ResponseWriter, r *http.Request)
 		result = append(result, map[string]any{
 			"hardware_kind":   candidate.HardwareKind,
 			"reader_name":     candidate.ReaderName,
+			"device_type":     discoveredDeviceType(candidate),
 			"discovery_key":   entry.ID,
 			"control_path":    controlPath,
 			"net_interface":   candidate.NetworkInterface,
@@ -1913,6 +1914,8 @@ func fillConfigFromPhysical(config *store.Device, entry device.Device) {
 		config.NetworkEnabled = false
 		config.SMSEnabled = true
 		config.VoWiFiEnabled = true
+	} else if modem.IsDJI4GUSB(candidate.VendorID, candidate.ProductID) {
+		config.DeviceType = store.DeviceTypeDJI4G
 	}
 	if config.Interface == "" {
 		config.Interface = candidate.NetworkInterface
@@ -1937,6 +1940,16 @@ func fillConfigFromPhysical(config *store.Device, entry device.Device) {
 	}
 }
 
+func discoveredDeviceType(candidate modem.Candidate) string {
+	if candidate.HardwareKind == "pcsc" {
+		return store.DeviceTypeUSBSIMReader
+	}
+	if modem.IsDJI4GUSB(candidate.VendorID, candidate.ProductID) {
+		return store.DeviceTypeDJI4G
+	}
+	return ""
+}
+
 func modemSummary(snapshot *device.Snapshot, phone string, phoneSource string) map[string]any {
 	if snapshot == nil {
 		return map[string]any{

internal/server/device_summary_test.go

@@ -6,10 +6,28 @@ import (
 	"time"
 
 	"vocat/internal/device"
+	"vocat/internal/modem"
 	"vocat/internal/store"
 	"vocat/internal/vowifi"
 )
 
+func TestFillConfigFromPhysicalClassifiesDJI4G(t *testing.T) {
+	config := store.Device{DeviceType: store.DeviceTypePCIeEC20EC25}
+	entry := device.Device{Candidate: modem.Candidate{
+		VendorID:  "2ca3",
+		ProductID: "4006",
+	}}
+
+	fillConfigFromPhysical(&config, entry)
+
+	if config.DeviceType != store.DeviceTypeDJI4G {
+		t.Fatalf("device type = %q, want %q", config.DeviceType, store.DeviceTypeDJI4G)
+	}
+	if got := discoveredDeviceType(entry.Candidate); got != store.DeviceTypeDJI4G {
+		t.Fatalf("discovered device type = %q, want %q", got, store.DeviceTypeDJI4G)
+	}
+}
+
 func TestConfiguredDeviceSummaryIgnoresVoWiFiRuntimeFromPreviousSIM(t *testing.T) {
 	database, err := store.Open(context.Background(), ":memory:")
 	if err != nil {

web/src/pages/DevicesPage.tsx

@@ -398,7 +398,7 @@ export default function DevicesPage() {
         modemImei: d.imei || "",
         usbPath: d.usbPath || "",
         deviceBackend: backend,
-		deviceType: isReader ? "usb_sim_reader" : prev.deviceType,
+		deviceType: d.deviceType || (isReader ? "usb_sim_reader" : prev.deviceType),
 		esimTransport: isReader ? "pcsc" : backend,
       };
     });

web/src/types.ts

@@ -174,6 +174,7 @@ export interface DeviceStatus {
 export interface DiscoveredDevice {
 	 hardwareKind?: string;
 	 readerName?: string;
+  deviceType?: DeviceType;
   discoveryKey: string;
   controlPath: string;
   netInterface: string;