diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/Application.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/Application.kt
index 27c7977..ae5f416 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/Application.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/Application.kt
@@ -7,6 +7,7 @@ import io.ktor.server.plugins.contentnegotiation.*
 import io.ktor.serialization.kotlinx.json.*
 import io.ktor.server.routing.*
 import io.ktor.server.websocket.*
+import org.apache.commons.logging.LogFactory
 import org.pavloveugene.iot.backend.config.AppConfig
 import org.pavloveugene.iot.backend.config.configureSerialization
 import org.pavloveugene.iot.backend.config.configureWebSockets
@@ -22,6 +23,7 @@ import kotlin.system.exitProcess
 
 fun main(args: Array<String>) {
 
+
     Database.init()
 
     runMigrations()
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/config/AppConfig.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/config/AppConfig.kt
index d06ec4d..6e86538 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/config/AppConfig.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/config/AppConfig.kt
@@ -17,4 +17,6 @@ object AppConfig {
     val dbUser = config.getString("ktor.database.user")
     val dbPassword = config.getString("ktor.database.password")
 
+    val storagePath = config.getString("iot.firmware.storage")
+
 }
\ No newline at end of file
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/db/Migration.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/db/Migration.kt
index 2e07247..f20db93 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/db/Migration.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/db/Migration.kt
@@ -1,10 +1,14 @@
 package org.pavloveugene.iot.backend.db
 
+import org.slf4j.LoggerFactory
+
 data class Migration(
     val version: Int,
     val sql: String
 )
 
+private val log= LoggerFactory.getLogger("DB Migrations")
+
 fun loadMigrations(): List<Migration> {
     val cl = Thread.currentThread().contextClassLoader
 
@@ -81,7 +85,7 @@ fun runMigrations() {
         for (m in migrations) {
             if (m.version in applied) continue
 
-            println("Applying migration V${m.version}")
+            log.info("Applying migration V${m.version}")
 
             try {
                 conn.autoCommit = false
@@ -90,7 +94,7 @@ fun runMigrations() {
 
                 for (stmt in statements) {
 
-                    println("Applying migration statement:\n $stmt\n========================")
+                    log.info("Applying migration statement:\n $stmt\n========================")
 
                     conn.createStatement().use { st ->
                         st.execute(stmt)
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/EventDto.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/EventDto.kt
index 967275c..18b90bd 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/EventDto.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/EventDto.kt
@@ -4,5 +4,11 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 data class EventDto (
-    val type: String
+    val t: String,
+    val v: Int,
+    val hp: Int,
+    val hl: Int,
+    val rs: Int,
+    val ip: Int,
+    val si: String,
 )
\ No newline at end of file
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/FirmwareUpdateCommandDto.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/FirmwareUpdateCommandDto.kt
new file mode 100644
index 0000000..b1eb91e
--- /dev/null
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/dto/FirmwareUpdateCommandDto.kt
@@ -0,0 +1,10 @@
+package org.pavloveugene.iot.backend.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class FirmwareUpdateCommandDto(
+    val t: String,
+    val u: String,
+    val s: String,
+)
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/FirmwareRoutes.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/FirmwareRoutes.kt
index eae1ae3..d2a91b7 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/FirmwareRoutes.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/FirmwareRoutes.kt
@@ -4,6 +4,7 @@ import io.ktor.http.HttpStatusCode
 import io.ktor.http.content.PartData
 import io.ktor.http.content.forEachPart
 import io.ktor.http.content.streamProvider
+import io.ktor.server.application.Application
 import io.ktor.server.application.call
 import io.ktor.server.request.receiveMultipart
 import io.ktor.server.response.respond
@@ -11,19 +12,62 @@ import io.ktor.server.response.respondFile
 import io.ktor.server.routing.Route
 import io.ktor.server.routing.get
 import io.ktor.server.routing.post
+import kotlinx.serialization.Serializable
+import org.pavloveugene.iot.backend.config.AppConfig.storagePath
 import org.pavloveugene.iot.backend.db.Database
+import org.pavloveugene.iot.backend.services.sendUpdateCommand
+import org.pavloveugene.iot.backend.services.updateUri
+import org.slf4j.LoggerFactory
 import java.io.File
 
-fun Route.firmwareRouting() {
-    uploadFirmware()
-    getFirmware()
+private val log = LoggerFactory.getLogger("FirmwareRoutes")
+
+fun Route.firmwareRouting(app: Application) {
+    uploadFirmware(app)
+    getFirmware(app)
+    otaTrigger()
+}
+
+private const val DEVICE_ID = "device_id"
+
+fun Route.otaTrigger() {
     post("/ota_trigger") {
-        // send WS command
+
+        val par = call.parameters[DEVICE_ID]
+        if (par.isNullOrBlank()) {
+            call.respond(HttpStatusCode.BadRequest, "Device id is mandatory")
+            return@post
+        }
+        val devId = par.toLong();
+        log.info("OTA trigger request. id: $par")
+
+        if (Database.queryOne("select count(0) cnt from devices where id=?", listOf(devId))
+                ?.get("cnt") as Number == 0
+        ) {
+            log.error("No device has id $devId in database")
+            call.respond(HttpStatusCode.BadRequest, "Invalid device id")
+            return@post
+        }
+        if (sendUpdateCommand(devId)) {
+            call.respond(HttpStatusCode.OK)
+        } else {
+            call.respond(HttpStatusCode.BadRequest, "Something went wrong")
+        }
     }
 }
 
-fun Route.uploadFirmware() {
+@Serializable
+data class UploadResponse(
+    val status: String,
+    val filename: String,
+    val version: Int
+)
+
+fun Route.uploadFirmware(app: Application) {
     post("/firmware_upload") {
+
+        log.info("Uploading Firmware file")
+
         val multipart = call.receiveMultipart()
 
         var deviceId: Long? = null
@@ -34,7 +78,7 @@ fun Route.uploadFirmware() {
             when (part) {
                 is PartData.FormItem -> {
                     when (part.name) {
-                        "device_id" -> deviceId = part.value.toLong()
+                        DEVICE_ID -> deviceId = part.value.toLong()
                     }
                 }
 
@@ -49,70 +93,90 @@ fun Route.uploadFirmware() {
             part.dispose()
         }
 
-        if (deviceId == null || fileBytes == null) {
-            call.respond(HttpStatusCode.BadRequest, "Missing fields")
+        if (deviceId == null) {
+            call.respond(HttpStatusCode.BadRequest, "Missing device id")
+            log.error("Device id is missing")
             return@post
         }
 
-        // 👉 генерим имя файла
-        val filename = "${java.util.UUID.randomUUID()}.bin"
-        val path = "storage/firmware/$filename"
-
-        // 👉 сохраняем файл
-        java.io.File(path).apply {
-            parentFile.mkdirs()
-            writeBytes(fileBytes!!)
+        val bytes = fileBytes ?: run {
+            call.respond(HttpStatusCode.BadRequest, "Missing file")
+            log.error("File is missing")
+            return@post
         }
 
-        // 👉 считаем sha256
-        val sha256 = java.security.MessageDigest
-            .getInstance("SHA-256")
-            .digest(fileBytes!!)
-            .joinToString("") { "%02x".format(it) }
+        log.info("Parameters ok")
 
-        // 👉 сохраняем в БД
-        while (true) {
-            version = ((Database.queryOne(
-                """
+        try {
+
+            // 👉 генерим имя файла
+            val baseDir = File(storagePath)
+            val filename = "${java.util.UUID.randomUUID()}.bin"
+            val file = File(baseDir, filename)
+            val path = file.path
+
+            file.parentFile.mkdirs()
+            file.writeBytes(bytes)
+
+            log.info("File created: $path")
+
+            // 👉 считаем sha256
+            val sha256 = java.security.MessageDigest
+                .getInstance("SHA-256")
+                .digest(bytes)
+                .joinToString("") { "%02x".format(it) }
+
+            log.info("sha-256= $sha256")
+
+            // 👉 сохраняем в БД
+            while (true) {
+                version = ((Database.queryOne(
+                    """
     select coalesce(max(version), 0) + 1 as v
     from firmware
     where device_id = ?
     """,
-                listOf(deviceId)
-            )?.get("v") as Number?)?.toInt() ?: 1)
+                    listOf(deviceId)
+                )?.get("v") as Number?)?.toInt() ?: 1)
 
-            try {
-                Database.execute(
-                    """
+                log.info("version: $version")
+
+                try {
+                    Database.execute(
+                        """
             insert into firmware (device_id, version, path, sha256, size)
             values (?, ?, ?, ?, ?)
         """, listOf(
-                        deviceId,
-                        version,
-                        path,
-                        sha256,
-                        fileBytes.size
+                            deviceId,
+                            version,
+                            path,
+                            sha256,
+                            bytes.size
+                        )
                     )
-                )
 
-                break
-            } catch (e: Exception) {
-                println("Retry insert firmware: ${e.message}")
+                    break
+                } catch (e: Exception) {
+                    log.info("Retry insert firmware: ${e.message}")
+                }
             }
-        }
 
-        call.respond(
-            mapOf(
-                "status" to "ok",
-                "filename" to filename,
-                "version" to version,
+            call.respond(
+                UploadResponse(
+                    status = "ok",
+                    filename = filename,
+                    version = version
+                )
             )
-        )
+        } catch (e: Exception) {
+            log.error(e.message, e)
+        }
     }
+
 }
 
-fun Route.getFirmware() {
-    get("/firmware/download") {
+fun Route.getFirmware(app: Application) {
+    get(updateUri) {
         val id = call.parameters["id"]!!.toInt()
 
         val row = Database.queryOne(
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/ProtocolWebSocket.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/ProtocolWebSocket.kt
index c027baf..7870c06 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/ProtocolWebSocket.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/routes/ProtocolWebSocket.kt
@@ -9,8 +9,11 @@ import kotlinx.serialization.json.Json
 import org.pavloveugene.iot.backend.config.AppConfig
 import org.pavloveugene.iot.backend.services.DeviceConnections
 import org.pavloveugene.iot.backend.services.ProtocolService
+import org.slf4j.LoggerFactory
 import java.io.IOException
 
+private val log= LoggerFactory.getLogger("ProtocolWebSocket")
+
 fun Route.protocolWebSocket() {
     val json = Json {
         ignoreUnknownKeys = false
@@ -20,7 +23,7 @@ fun Route.protocolWebSocket() {
 
     webSocket(AppConfig.wsPath) {
 
-        println("WS connected")
+        log.info("WS connected")
 
         var devId: UInt? = null
 
@@ -32,34 +35,36 @@ fun Route.protocolWebSocket() {
                     val msg = try {
                         json.decodeFromString<MessageDto>(text)
                     } catch (e: Exception) {
-                        println("WS decode error: ${e.message}")
+                        log.info("WS decode error: ${e.message}")
                         safeSend("""{"error":"invalid"}""")
                         continue
                     }
 
                     try {
                         devId = msg.d
-                        protocolService.handleMessage(msg, this)
+                        protocolService.handleMessage(msg, this, call.request)
                     } catch (e: Exception) {
-                        println("WS handler error: ${e.message}")
+                        log.info("WS handler error: ${e.message}")
                     }
                 }
             }
         } catch (e: CancellationException) {
             // нормальный shutdown — молчим
         } catch (e: IOException) {
-            println("WS disconnected: ${e.message}")
+            log.info("WS disconnected: ${e.message}")
         } catch (e: Exception) {
-            println("WS error: ${e.message}")
+            log.info("WS error: ${e.message}")
         } finally {
             devId?.let {
                 DeviceConnections.unregister(devId)
-                println("WS disconnected: $it")
+                log.info("WS disconnected: $it")
             }
         }
     }
 }
 
+
+
 suspend fun DefaultWebSocketServerSession.safeSend(text: String) {
     try {
         send(text)
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/CleanupService.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/CleanupService.kt
index c7387b4..83a7da9 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/CleanupService.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/CleanupService.kt
@@ -1,14 +1,17 @@
 package org.pavloveugene.iot.backend.services
 
 import org.pavloveugene.iot.backend.db.Database
+import org.slf4j.LoggerFactory
 import java.sql.SQLException
 
+private val log  = LoggerFactory.getLogger("CleanupService")
+
 fun executeCleanup() {
     val ds = Database.dataSource
     val start = System.currentTimeMillis()
     val cutoff = start / 1000 - 60 * 60 * 24 * 2
 
-    println("Begin cleanup")
+    log.info("Begin cleanup")
 
     ds.connection.use { conn ->
         conn.autoCommit = false
@@ -17,7 +20,8 @@ fun executeCleanup() {
             var total = 0
 
             do {
-                val deleted = conn.prepareStatement("""
+                val deleted = conn.prepareStatement(
+                    """
                     delete t
                     from telemetry t
                     join (
@@ -26,7 +30,8 @@ fun executeCleanup() {
                         where ts < ? and processed = true
                         limit 1000
                     ) p on p.id = t.id
-                """.trimIndent()).use { ps ->
+                """.trimIndent()
+                ).use { ps ->
                     ps.setLong(1, cutoff)
                     ps.executeUpdate()
                 }
@@ -34,7 +39,7 @@ fun executeCleanup() {
                 total += deleted
 
                 if (deleted > 0) {
-                    println("Deleted $deleted rows (total $total)")
+                    log.info("Deleted $deleted rows (total $total)")
                 }
 
                 conn.commit()
@@ -49,5 +54,5 @@ fun executeCleanup() {
         }
     }
 
-    println("Cleanup complete in ${System.currentTimeMillis() - start} ms")
+    log.info("Cleanup complete in ${System.currentTimeMillis() - start} ms")
 }
\ No newline at end of file
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/DeviceConnection.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/DeviceConnection.kt
index c3cfa6b..ff51ed6 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/DeviceConnection.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/DeviceConnection.kt
@@ -1,8 +1,11 @@
 package org.pavloveugene.iot.backend.services
 
+import io.ktor.server.request.ApplicationRequest
 import io.ktor.websocket.WebSocketSession
 
 data class DeviceConnection(
     val session: WebSocketSession,
-    var lastSeen: Long
+    val request: ApplicationRequest,
+    var lastId: UInt = 0u,
+    var lastSeen: Long,
 )
\ No newline at end of file
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/KtorServer.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/KtorServer.kt
index 37ad005..17807d7 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/KtorServer.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/KtorServer.kt
@@ -16,13 +16,18 @@ import org.pavloveugene.iot.backend.routes.protocolWebSocket
 import java.time.Duration
 import io.ktor.server.plugins.compression.*
 import org.pavloveugene.iot.backend.routes.firmwareRouting
+import org.slf4j.LoggerFactory
+
+private val log  = LoggerFactory.getLogger("KtorServer")
 
 fun startKtorServer() {
+
     val server = embeddedServer(
         Netty,
         port = AppConfig.serverPort,
         host = AppConfig.serverHost,
     ) {
+
         install(ContentNegotiation) {
             json()
         }
@@ -35,18 +40,19 @@ fun startKtorServer() {
         }
 
         routing {
+            log.info("CONFIG = ${application.environment.config.toMap()}")
             protocolRoutes()
             protocolWebSocket()
-            firmwareRouting()
+            firmwareRouting(application)
         }
     }
 
     Runtime.getRuntime().addShutdownHook(Thread {
-        println("Shutting down...")
+        log.info("Shutting down...")
         try {
             server.stop(1000, 2000)
         } catch (e: Exception) {
-            println("Shutdown error: ${e.message}")
+            log.info("Shutdown error: ${e.message}")
         }
     })
 
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/NormalizeService.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/NormalizeService.kt
index b5cdd25..5142de2 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/NormalizeService.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/NormalizeService.kt
@@ -1,6 +1,9 @@
 package org.pavloveugene.iot.backend.services
 
 import org.pavloveugene.iot.backend.db.Database
+import org.slf4j.LoggerFactory
+
+private val log  = LoggerFactory.getLogger("NormalizeService")
 
 fun runNormalizeLoop() {
     var total = 0
@@ -9,10 +12,10 @@ fun runNormalizeLoop() {
     do {
         val count = normalizeBatch()
         total += count
-        println("Processed batch: $count")
+        log.info("Processed batch: $count")
     } while (count > 0)
 
-    println("Done. Total processed: $total in ${System.currentTimeMillis() - start} ms")
+    log.info("Done. Total processed: $total in ${System.currentTimeMillis() - start} ms")
 
 }
 
@@ -124,7 +127,7 @@ fun verifyData(): Boolean {
     val ds = Database.dataSource
     var ret = true;
 
-    println("Executing verification")
+    log.info("Executing verification")
 
     ds.connection.use { conn ->
 
@@ -155,9 +158,9 @@ fun verifyData(): Boolean {
                     val count = rs.getInt(1)
                     ret = count == 0
                     if (ret) {
-                        println("All ok!")
+                        log.info("All ok!")
                     } else {
-                        println("$count errors detected")
+                        log.info("$count errors detected")
                     }
                 }
 
@@ -181,7 +184,7 @@ fun verifyData(): Boolean {
         }
     }
 
-    println("Verification complete")
+    log.info("Verification complete")
 
     return ret
 }
\ No newline at end of file
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/ProtocolService.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/ProtocolService.kt
index 2fb7601..390ed3e 100644
--- a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/ProtocolService.kt
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/ProtocolService.kt
@@ -1,7 +1,7 @@
 package org.pavloveugene.iot.backend.services
 
 import MessageDto
-import io.ktor.server.websocket.WebSocketServerSession
+import io.ktor.server.request.ApplicationRequest
 import io.ktor.websocket.WebSocketSession
 import kotlinx.serialization.builtins.ListSerializer
 import kotlinx.serialization.builtins.serializer
@@ -9,42 +9,58 @@ import kotlinx.serialization.json.Json
 import org.pavloveugene.iot.backend.db.Database
 import org.pavloveugene.iot.backend.dto.EventDto
 import org.pavloveugene.iot.backend.dto.TelemetryDto
+import org.slf4j.LoggerFactory
+import java.net.InetAddress
+
+private val log = LoggerFactory.getLogger("ProtocolService")
 
 class ProtocolService(
     private val json: Json
 ) {
 
-    fun handleMessage(msg: MessageDto, session: WebSocketSession) {
+    fun handleMessage(msg: MessageDto, session: WebSocketSession, request: ApplicationRequest) {
         when (msg.t) {
             MessageType.TELEMETRY -> {
                 handleTelemetry(msg)
             }
 
             MessageType.EVENT -> {
-                println("=== EVENT ===")
-                println(msg.p)
-                handleEvent(msg, session)
+                log.info("=== EVENT ===")
+                log.info("${msg.p}")
+                handleEvent(msg, session, request)
             }
 
             MessageType.COMMAND -> {
-                println("=== COMMAND ===")
-                println(msg.p)
+                log.info("=== COMMAND ===")
+                log.info("${msg.p}")
             }
         }
     }
 
-    private fun handleEvent(msg: MessageDto, session: WebSocketSession) {
+    private fun intToIp(ip: Int): String {
+        val reverse = Integer.reverseBytes(ip)
+        val bytes = byteArrayOf(
+            (reverse shr 24).toByte(),
+            (reverse shr 16).toByte(),
+            (reverse shr 8).toByte(),
+            reverse.toByte()
+        )
+        return InetAddress.getByAddress(bytes).hostAddress
+    }
+
+    private fun handleEvent(msg: MessageDto, session: WebSocketSession, request: ApplicationRequest) {
         val payload = json.decodeFromJsonElement(EventDto.serializer(), msg.p)
-        when (payload.type) {
-            "HB" -> {
-                println("=== HB devId = ${msg.d} ===")
+        when (payload.t) {
+            "hb" -> {
+                log.info("=== HB devId = ${msg.d} IP = ${intToIp(payload.ip)} ===")
 
                 val connection = DeviceConnections.get(msg.d)
                 if (connection == null) {
                     DeviceConnections.register(
                         msg.d, DeviceConnection(
                             session = session,
-                            lastSeen = System.currentTimeMillis()
+                            lastSeen = System.currentTimeMillis(),
+                            request = request
                         )
                     )
                 } else {
@@ -85,18 +101,18 @@ class ProtocolService(
                 }
 
                 if (!isEnabled) {
-                    println("device ${msg.d} locked, message ignored")
+                    log.info("device ${msg.d} locked, message ignored")
                     conn.commit()
                     return
                 }
 
                 val payload = json.decodeFromJsonElement(TelemetryDto.serializer(), msg.p)
 
-                println("=== TELEMETRY ===")
-                println("device=${msg.d}")
-                println("ts=${msg.ts}")
-                println("metric=${payload.m}")
-                println("values=${payload.v}")
+                log.info("=== TELEMETRY ===")
+                log.info("device=${msg.d}")
+                log.info("ts=${msg.ts}")
+                log.info("metric=${payload.m}")
+                log.info("values=${payload.v}")
 
                 // insert telemetry
                 conn.prepareStatement(
diff --git a/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/UpdateTrigger.kt b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/UpdateTrigger.kt
new file mode 100644
index 0000000..22ea7f9
--- /dev/null
+++ b/backend/src/main/kotlin/org/pavloveugene/iot/backend/services/UpdateTrigger.kt
@@ -0,0 +1,136 @@
+package org.pavloveugene.iot.backend.services
+
+import MessageDto
+import MessageType
+import io.ktor.server.plugins.origin
+import io.ktor.util.date.getTimeMillis
+import io.ktor.websocket.send
+import kotlinx.serialization.json.Json
+import org.pavloveugene.iot.backend.db.Database
+import org.pavloveugene.iot.backend.db.Database.queryOne
+import org.pavloveugene.iot.backend.dto.FirmwareUpdateCommandDto
+import org.slf4j.LoggerFactory
+
+private val log = LoggerFactory.getLogger("OTA")
+
+const val updateUri = "/firmware/download"
+
+suspend fun sendUpdateCommand(
+    devId: Long
+): Boolean {
+    var ret = true
+
+    log.info("Sending update command to device: $devId")
+
+    val ver = queryOne(
+        """
+        select *
+        from firmware
+        where device_id = ?
+        order by version desc
+        limit 1
+    """.trimIndent(), listOf(devId)
+    )
+
+    if (ver == null) {
+        log.error("No firmware uploaded for device: $devId.")
+        ret = false
+    } else {
+        val firmware_id = ver["id"] as Int
+        val sha256 = ver["sha256"] as String
+
+        var update = queryOne(
+            """
+        select fu.*
+        from firmware_updates fu
+        where fu.firmware_id = ?
+                """.trimIndent(),
+            listOf(firmware_id)
+        )
+
+        if (update == null) {
+            val update_id = Database.insertAndReturnId(
+                """
+                insert into firmware_updates (firmware_id, status)
+                values (?, ?)
+            """.trimIndent(),
+                listOf(firmware_id, "pending")
+            )
+
+            update = queryOne(
+                """
+                select fu.*
+                from firmware_updates fu
+                where fu.id = ?
+                """.trimIndent(),
+                listOf(update_id),
+            )
+        }
+
+        if (update == null) {
+            ret = false
+            log.error("No firmware sent to device: $devId. Something went wrong.")
+        } else {
+            val status = update["status"] as String
+
+            if (status == "pending") {
+
+                val deviceConnection = DeviceConnections.get(devId.toUInt())
+                if (deviceConnection == null) {
+                    ret = false
+                    log.warn("No firmware sent to device: $devId. Device not connected.")
+                } else {
+                    val origin = deviceConnection.request.origin
+                    val portPart =
+                        if (origin.serverPort == 80 || origin.serverPort == 443) ""
+                        else ":${origin.serverPort}"
+
+                    val url = "${origin.scheme}://${origin.serverHost}$portPart$updateUri?id=${firmware_id}"
+
+                    val updPayload = FirmwareUpdateCommandDto(
+                        t = "fw",
+                        u = url,
+                        s = sha256,
+                    )
+
+                    deviceConnection.lastId++
+
+                    val updateCommand = MessageDto(
+                        v = 1,
+                        id = deviceConnection.lastId,
+                        d = devId.toUInt(),
+                        t = MessageType.COMMAND,
+                        ts = getTimeMillis(),
+                        p = Json.encodeToJsonElement(FirmwareUpdateCommandDto.serializer(), updPayload),
+                    )
+
+                    val cmdJson: String = Json.encodeToJsonElement(
+                        MessageDto.serializer(),
+                        updateCommand
+                    ).toString();
+
+                    try {
+                        deviceConnection.session.send(cmdJson)
+
+                        Database.execute(
+                            """
+                        update firmware_updates
+                        set status = 'sent'
+                        where id = ?
+                        """.trimIndent(), listOf(update["id"])
+                        )
+
+                        log.info("Firmware update sent for device: $devId. Command: $cmdJson")
+
+                    } catch (e: Exception) {
+                        ret = false
+                        log.error("Error updating device $devId", e)
+                    }
+
+                }
+            }
+        }
+
+    }
+    return ret
+}
\ No newline at end of file
diff --git a/esp32/CMakeLists.txt b/esp32/CMakeLists.txt
index 67c0a87..3bd4463 100644
--- a/esp32/CMakeLists.txt
+++ b/esp32/CMakeLists.txt
@@ -4,6 +4,7 @@ cmake_minimum_required(VERSION 3.22)
 
 file(READ "${CMAKE_SOURCE_DIR}/version.txt" PROJECT_VER)
 string(STRIP "${PROJECT_VER}" PROJECT_VER)
+add_compile_definitions(FW_VERSION=${PROJECT_VER})
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(esp32)
diff --git a/esp32/main/CMakeLists.txt b/esp32/main/CMakeLists.txt
index 0a9c12d..d3e3a22 100644
--- a/esp32/main/CMakeLists.txt
+++ b/esp32/main/CMakeLists.txt
@@ -29,6 +29,7 @@ idf_component_register(
         esp_driver_gpio
         esp_http_client
         app_update
+        mbedtls
 )
 # добавляем кастомный Kconfig
 set(COMPONENT_KCONFIG "Kconfig")
\ No newline at end of file
diff --git a/esp32/main/heartbeat_task.cpp b/esp32/main/heartbeat_task.cpp
index 893e50a..64fa80a 100644
--- a/esp32/main/heartbeat_task.cpp
+++ b/esp32/main/heartbeat_task.cpp
@@ -22,9 +22,11 @@ static void heartbeat_task(void* arg)
             time(&now);
 
             protocol_send_event_hb((uint32_t)now);
+            vTaskDelay(pdMS_TO_TICKS(30000)); // 30 сек
+        } else
+        {
+            vTaskDelay(pdMS_TO_TICKS(2000));
         }
-
-        vTaskDelay(pdMS_TO_TICKS(10000)); // 10 сек
     }
 }
 
diff --git a/esp32/main/ota.cpp b/esp32/main/ota.cpp
index 9df6c3f..fbfb512 100644
--- a/esp32/main/ota.cpp
+++ b/esp32/main/ota.cpp
@@ -8,57 +8,102 @@
 #include "ws.h"
 #include "heartbeat_task.h"
 #include "fw_command.h"
+#include "psa/crypto.h"
 
 static TaskHandle_t ota_task_handle = nullptr;
 static char url_copy[256];
 static char sha256[65];
 
+#define TAG "OTA"
+
 void perform_ota(void* par)
 {
+    sampler_task_stop();
+    sender_task_stop();
+    heartbeat_task_stop();
+    ws_disconnect();
+
+    ESP_LOGI(TAG, "OTA task started");
     esp_ota_handle_t ota_handle;
     uint8_t buf[1024];
     int read_bytes;
     const esp_partition_t* partition = nullptr;
+    int content_length = 0;
+    psa_hash_operation_t op = PSA_HASH_OPERATION_INIT;
 
     const char* url = static_cast<const char*>(par);
 
+    ESP_LOGI(TAG, "URL: %s", url);
+
     esp_http_client_config_t config = {};
     config.url = url;
     config.timeout_ms = 5000;
     config.buffer_size = 1024;
 
-
     esp_http_client_handle_t client = esp_http_client_init(&config);
 
+    ESP_LOGI(TAG, "HTTP init complete");
+
+
     if (esp_http_client_open(client, 0) != ESP_OK)
     {
         goto cleanup;
     }
 
+    ESP_LOGI(TAG, "HTTP connection established");
+
+    content_length = esp_http_client_fetch_headers(client);
+    ESP_LOGI(TAG, "content_length=%d", content_length);
+
     partition = esp_ota_get_next_update_partition(nullptr);
 
+    ESP_LOGI(TAG, "OTA update partition selected %s (offset 0x%08x)", partition->label, partition->address);
+
     if (esp_ota_begin(partition, OTA_SIZE_UNKNOWN, &ota_handle) != ESP_OK)
     {
         goto cleanup;
     }
 
-    while ((read_bytes = esp_http_client_read(client, (char*)buf, sizeof(buf))) > 0)
+    psa_crypto_init();
+    psa_hash_setup(&op, PSA_ALG_SHA_256);
+
+    ESP_LOGI(TAG, "OTA update started");
+
+    while (1)
     {
-        if (esp_ota_write(ota_handle, buf, read_bytes) != ESP_OK)
+        int data_read = esp_http_client_read(client, (char*)buf, sizeof(buf));
+
+        if (data_read < 0)
         {
-            esp_ota_end(ota_handle);
+            ESP_LOGE(TAG, "read error");
+            break;
+        }
+        else if (data_read == 0)
+        {
+            ESP_LOGI(TAG, "download finished");
+            break;
+        }
+
+        ESP_LOGI(TAG, "write chunk: %d bytes", data_read);
+
+        if (esp_ota_write(ota_handle, buf, data_read) != ESP_OK)
+        {
+            ESP_LOGE(TAG, "flash write failed");
             goto cleanup;
         }
+        if (psa_hash_update(&op, buf, data_read) != PSA_SUCCESS) {
+            ESP_LOGE(TAG, "hash update failed");
+        }
     }
 
+    ESP_LOGI(TAG, "finalizing...");
+
     if (esp_ota_end(ota_handle) == ESP_OK)
     {
         uint8_t hash[32];
+        size_t hash_len;
 
-        if (esp_partition_get_sha256(partition, hash) != ESP_OK)
-        {
-            goto cleanup;
-        }
+        psa_hash_finish(&op, hash, sizeof(hash), &hash_len);
 
         // переводим в hex
         char hash_str[65];
@@ -68,16 +113,24 @@ void perform_ota(void* par)
         }
         hash_str[64] = '\0';
 
+        ESP_LOGI(TAG, "sha256 = %s. Comparing...", hash_str);
+
         // сравнение
         if (strncmp(hash_str, sha256, 64) != 0)
         {
-            printf("SHA256 mismatch!\n");
+            ESP_LOGE(TAG, "SHA256 mismatch!");
             goto cleanup;
         }
 
+        ESP_LOGI(TAG, "set boot partition");
         esp_ota_set_boot_partition(partition);
+        ESP_LOGI(TAG, "restart pending");
         esp_restart();
     }
+    else
+    {
+        ESP_LOGE(TAG, "ota_end failed");
+    }
 
 cleanup:
     esp_http_client_cleanup(client);
@@ -89,10 +142,6 @@ void ota_task_start(const fw_cmd_t* cmd)
 {
     strncpy(url_copy, cmd->url, sizeof(url_copy));
     strncpy(sha256, cmd->sha256, sizeof(sha256));
-    sampler_task_stop();
-    sender_task_stop();
-    heartbeat_task_stop();
-    ws_disconnect();
     if (ota_task_handle == nullptr)
     {
         xTaskCreate(
diff --git a/esp32/main/protocol.cpp b/esp32/main/protocol.cpp
index ed843a5..76c8ddc 100644
--- a/esp32/main/protocol.cpp
+++ b/esp32/main/protocol.cpp
@@ -3,6 +3,8 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <inttypes.h>
+#include "esp_wifi.h"
+#include "esp_netif.h"
 
 #define PROTOCOL_VERSION 1
 
@@ -195,16 +197,45 @@ uint32_t protocol_next_id()
 
 void protocol_send_event_hb(int64_t ts)
 {
-    // формируешь JSON строго по контракту
+    char buf[256];
 
-    // пример:
-    char buf[128];
+    wifi_ap_record_t ap;
+    esp_wifi_sta_get_ap_info(&ap);
+
+    int rssi = ap.rssi;
+    const char *ssid = (const char *)ap.ssid;
+
+    esp_netif_ip_info_t ip_info;
+    esp_netif_t *netif = esp_netif_get_handle_from_ifkey("WIFI_STA_DEF");
+
+    esp_netif_get_ip_info(netif, &ip_info);
+
+    uint32_t ip = ip_info.ip.addr;
+
+    size_t heap_free = heap_caps_get_free_size(MALLOC_CAP_DEFAULT);
+    size_t heap_largest = heap_caps_get_largest_free_block(MALLOC_CAP_DEFAULT);
 
     uint32_t id = protocol_next_id();
 
     snprintf(buf, sizeof(buf),
-        "{\"v\":1,\"id\":%" PRIu32 ",\"t\":\"e\",\"ts\":%" PRIu64 ",\"d\":%u,\"p\":{\"type\":\"hb\"}}",
-        id, ts, CONFIG_DEVICE_ID);
+    "{\"v\":1,\"id\":%" PRIu32 ",\"t\":\"e\",\"ts\":%" PRIu64 ",\"d\":%u,"
+    "\"p\":{"
+        "\"t\":\"hb\","
+        "\"v\":%u,"
+        "\"hp\":%u,"
+        "\"hl\":%u,"
+        "\"rs\":%d,"
+        "\"ip\":%" PRIu32 ","
+        "\"si\":\"%s\""
+    "}}",
+    id, ts, CONFIG_DEVICE_ID,
+    FW_VERSION,
+    heap_free,
+    heap_largest,
+    rssi,
+    ip,
+    ssid
+);
 
     ws_send(buf);
 }
diff --git a/esp32/version.txt b/esp32/version.txt
index 56a6051..301160a 100644
--- a/esp32/version.txt
+++ b/esp32/version.txt
@@ -1 +1 @@
-1
\ No newline at end of file
+8
\ No newline at end of file