diff --git a/cmd/dev-server/main.go b/cmd/dev-server/main.go
index 4ffb717..19dfdec 100644
--- a/cmd/dev-server/main.go
+++ b/cmd/dev-server/main.go
@@ -112,6 +112,18 @@ func handleCameraCoveredAlarm(sPack *n9m.SmartPackage, pack n9m.Package, respons
 	return nil
 }
 
+func handleSPI(_ *n9m.SmartPackage, pack n9m.Package) (err error) {
+	var params n9m.SpiParameters
+
+	if err = pack.GetParametersAs(&params); err != nil {
+		return
+	}
+
+	fmt.Printf("%+v\n", params)
+
+	return
+}
+
 func createSmartPackage(conn net.Conn) (pack *n9m.SmartPackage) {
 	pack = n9m.NewSmartPackage(conn)
 
@@ -120,6 +132,7 @@ func createSmartPackage(conn net.Conn) (pack *n9m.SmartPackage) {
 	pack.AddJSONHandler("CERTIFICATE", "CONNECT", handleCertificateConnect)
 	pack.AddJSONHandler("CERTIFICATE", "KEEPALIVE", handleKeepAlive)
 	pack.AddJSONHandler("CONFIGMODEL", "GET", handleGetConfig)
+	pack.AddJSONHandler("DEVEMM", "SPI", handleSPI)
 
 	pack.AddAlarmHandler(n9m.AlarmTypeMotionDetection, handleUselessAlarms)
 
diff --git a/devemm.go b/devemm.go
index 36db1e9..21a4437 100644
--- a/devemm.go
+++ b/devemm.go
@@ -1,5 +1,12 @@
 package n9m
 
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"time"
+)
+
 /*
 
 // main server util
@@ -36,3 +43,172 @@ func (e *Package) ResponseGeolocation(errorCode int, errorCause string, serial i
 }
 
 */
+
+// 3.4.5.28
+type SpiParameters struct {
+	DriveFlag    uint            `json:"T"`
+	DataMask     uint            `json:"M"`
+	Position     GPSData         `json:"P"`
+	DeviceStatus SpiDeviceStatus `json:"S"`
+}
+
+// 3.4.5.28.1
+type SpiDeviceStatus struct {
+	Status3G            uint                `json:"G3"`
+	Status3GStrength    uint                `json:"G3S"`
+	Status4G            uint                `json:"G4"`
+	Status4GStrength    uint                `json:"G4S"`
+	WIFIStatus          uint                `json:"W"`
+	WIFIStrength        uint                `json:"WS"`
+	Voltage             float64             `json:"V"`
+	DeviceTemperature   float64             `json:"DT"`
+	IndoorTemperature   float64             `json:"TC"`
+	Speed               float64             `json:"S"`
+	KeyIgnitionState    uint                `json:"SW"`
+	RecordStatus        []uint              `json:"RE"`
+	Time                time.Time           `json:"T"`
+	StorageDeviceNumber uint                `json:"STC"`
+	StorageDeviceInfo   []StorageDeviceInfo `json:"SINFO"`
+	VideoLossStatus     []uint              `json:"VS"`
+	Humidity            float64             `json:"H"`
+	TotalMileage        float64             `json:"TM"`
+	HardDriveHeating    uint                `json:"HTR"`
+}
+
+func (g *SpiDeviceStatus) MarshalJSON() ([]byte, error) {
+	var alias struct {
+		Status3G            uint                `json:"G3"`
+		Status3GStrength    uint                `json:"G3S"`
+		Status4G            uint                `json:"G4"`
+		Status4GStrength    uint                `json:"G4S"`
+		WIFIStatus          uint                `json:"W"`
+		WIFIStrength        uint                `json:"WS"`
+		Voltage             uint                `json:"V"`
+		DeviceTemperature   uint                `json:"DT"`
+		IndoorTemperature   uint                `json:"TC"`
+		Speed               uint                `json:"S"`
+		SpeedUnits          uint                `json:"SU"`
+		KeyIgnitionState    uint                `json:"SW"`
+		RecordStatus        []uint              `json:"RE"`
+		Time                string              `json:"T"`
+		StorageDeviceNumber uint                `json:"STC"`
+		StorageDeviceInfo   []StorageDeviceInfo `json:"SINFO"`
+		VideoLossStatus     []uint              `json:"VS"`
+		Humidity            uint                `json:"H"`
+		TotalMileage        string              `json:"TM"`
+		HardDriveHeating    uint                `json:"HTR"`
+	}
+
+	convert := func(v float64) uint {
+		if v < 0 {
+			return uint(-v * 100)
+		} else {
+			return uint((v + 100) * 100)
+		}
+	}
+
+	alias.Status3G = g.Status3G
+	alias.Status3GStrength = g.Status3GStrength
+	alias.Status4G = g.Status4G
+	alias.Status4GStrength = g.Status4GStrength
+	alias.WIFIStatus = g.WIFIStatus
+	alias.WIFIStrength = g.WIFIStrength
+	alias.Voltage = uint(g.Voltage * 100)
+	alias.DeviceTemperature = convert(g.DeviceTemperature)
+	alias.IndoorTemperature = convert(g.IndoorTemperature)
+	alias.Speed = uint(g.Speed * 100)
+	alias.SpeedUnits = 0
+	alias.KeyIgnitionState = g.KeyIgnitionState
+	alias.RecordStatus = g.RecordStatus
+	alias.Time = g.Time.Format("20060102150405")
+	alias.StorageDeviceNumber = g.StorageDeviceNumber
+	alias.StorageDeviceInfo = g.StorageDeviceInfo
+	alias.VideoLossStatus = g.VideoLossStatus
+	alias.Humidity = uint(g.Humidity * 10000)
+	alias.TotalMileage = fmt.Sprintf("%.6f", g.TotalMileage)
+	alias.HardDriveHeating = g.HardDriveHeating
+
+	return json.Marshal(alias)
+}
+
+func (g *SpiDeviceStatus) UnmarshalJSON(data []byte) (err error) {
+	var alias struct {
+		Status3G            uint                `json:"G3"`
+		Status3GStrength    uint                `json:"G3S"`
+		Status4G            uint                `json:"G4"`
+		Status4GStrength    uint                `json:"G4S"`
+		WIFIStatus          uint                `json:"W"`
+		WIFIStrength        uint                `json:"WS"`
+		Voltage             uint                `json:"V"`
+		DeviceTemperature   uint                `json:"TD"`
+		IndoorTemperature   uint                `json:"TC"`
+		Speed               uint                `json:"S"`
+		SpeedUnits          uint                `json:"SU"`
+		KeyIgnitionState    uint                `json:"SW"`
+		RecordStatus        []uint              `json:"RE"`
+		Time                string              `json:"T"`
+		StorageDeviceNumber uint                `json:"STC"`
+		StorageDeviceInfo   []StorageDeviceInfo `json:"SINFO"`
+		VideoLossStatus     []uint              `json:"VS"`
+		Humidity            uint                `json:"H"`
+		TotalMileage        string              `json:"TM"`
+		HardDriveHeating    uint                `json:"HTR"`
+	}
+
+	if err = json.Unmarshal(data, &alias); err != nil {
+		return
+	}
+
+	convert := func(v uint) float64 {
+		if v < 10000 {
+			return -float64(v) / 100
+		} else {
+			return float64(v-10000) / 100
+		}
+	}
+
+	g.Status3G = alias.Status3G
+	g.Status3GStrength = alias.Status3GStrength
+	g.Status4G = alias.Status4G
+	g.Status4GStrength = alias.Status4GStrength
+	g.WIFIStatus = alias.WIFIStatus
+	g.WIFIStrength = alias.WIFIStrength
+	g.Voltage = float64(alias.Voltage) / 100
+	g.DeviceTemperature = convert(alias.DeviceTemperature)
+	g.IndoorTemperature = convert(alias.IndoorTemperature)
+
+	g.Speed = float64(alias.Speed) / 100.0
+	switch alias.SpeedUnits {
+	case 0:
+		break
+	case 1:
+		g.Speed *= 1.609
+	default:
+		return fmt.Errorf("Strange speed units")
+	}
+
+	g.KeyIgnitionState = alias.KeyIgnitionState
+	g.RecordStatus = alias.RecordStatus
+	g.Time, _ = time.Parse("20060102150405", alias.Time)
+	g.StorageDeviceNumber = alias.StorageDeviceNumber
+	g.StorageDeviceInfo = alias.StorageDeviceInfo
+	g.VideoLossStatus = alias.VideoLossStatus
+	g.Humidity = float64(alias.Humidity) / 10000
+
+	if g.TotalMileage, err = strconv.ParseFloat(alias.TotalMileage, 64); err != nil {
+		return fmt.Errorf("invalid longitude: %w", err)
+	}
+
+	g.HardDriveHeating = alias.HardDriveHeating
+
+	return nil
+}
+
+// 3.4.5.28.3
+type StorageDeviceInfo struct {
+	Type         uint `json:"T"`
+	MediaTime    uint `json:"O"`
+	Status       uint `json:"S"`
+	Capacity     uint `json:"TS"`
+	FreeCapacity uint `json:"LS"`
+}