diff --git a/app/src/main/java/com/shuwei/intelligent/shelves/serial/ProtocolConstants.kt b/app/src/main/java/com/shuwei/intelligent/shelves/serial/ProtocolConstants.kt
index 5b3d43a..efdfc1e 100644
--- a/app/src/main/java/com/shuwei/intelligent/shelves/serial/ProtocolConstants.kt
+++ b/app/src/main/java/com/shuwei/intelligent/shelves/serial/ProtocolConstants.kt
@@ -1,5 +1,7 @@
 package com.shuwei.intelligent.shelves.serial
 
+import com.shuwei.intelligent.shelves.App
+
 /**
  * 串口通信协议常量定义
  * 统一管理所有协议头、协议尾、各类指令及帧解析偏移量
@@ -63,7 +65,11 @@ object ProtocolConstants {
     const val DEVICE_STATUS_WEIGHT_OFFSET = HEADER.length + 14
 
     /** 货架数量（每侧5格，共10格，协议中12组） */
-    const val SHELF_SENSOR_COUNT = 12
+    fun shelfSensorCount(): Int {
+        return if (device2Columns.contains(App.deviceId)) 12
+        else if (device3Columns.contains(App.deviceId)) 24
+        else 0
+    }
 
     /** 每组重量数据字节数（十六进制字符数） */
     const val BYTES_PER_WEIGHT = 8
@@ -72,10 +78,18 @@ object ProtocolConstants {
     const val TEMPERATURE_FIELD_LEN = 2
 
     /** 心跳帧最小有效长度 */
-    const val HEARTBEAT_MIN_LENGTH = 200
+    fun heartbeatMinLength(): Int {
+        return if (device2Columns.contains(App.deviceId)) 200
+        else if (device3Columns.contains(App.deviceId)) 296
+        else 0
+    }
 
     /** 心跳帧中温度字段起始偏移（经协议分析得出，前面含重量+其他传感器数据） */
-    const val HEARTBEAT_TEMPERATURE_START = 158
+    fun heartbeatTemperatureStart(): Int {
+        return if (device2Columns.contains(App.deviceId)) 158
+        else if (device3Columns.contains(App.deviceId)) 158+96
+        else 0
+    }
 
     /** 激活请求体有效长度 */
     const val ACTIVATE_BODY_LENGTH = 44
diff --git a/app/src/main/java/com/shuwei/intelligent/shelves/serial/SerialProtocolHandler.kt b/app/src/main/java/com/shuwei/intelligent/shelves/serial/SerialProtocolHandler.kt
index e6a42a3..50b7d67 100644
--- a/app/src/main/java/com/shuwei/intelligent/shelves/serial/SerialProtocolHandler.kt
+++ b/app/src/main/java/com/shuwei/intelligent/shelves/serial/SerialProtocolHandler.kt
@@ -20,10 +20,7 @@ import com.shuwei.intelligent.shelves.serial.ProtocolConstants.DEVICE_STATUS_WEI
 import com.shuwei.intelligent.shelves.serial.ProtocolConstants.FIX_BODY_LENGTH
 import com.shuwei.intelligent.shelves.serial.ProtocolConstants.FOOTER
 import com.shuwei.intelligent.shelves.serial.ProtocolConstants.HEADER
-import com.shuwei.intelligent.shelves.serial.ProtocolConstants.HEARTBEAT_MIN_LENGTH
-import com.shuwei.intelligent.shelves.serial.ProtocolConstants.HEARTBEAT_TEMPERATURE_START
 import com.shuwei.intelligent.shelves.serial.ProtocolConstants.HEARTBEAT_WEIGHT_OFFSET
-import com.shuwei.intelligent.shelves.serial.ProtocolConstants.SHELF_SENSOR_COUNT
 import com.shuwei.intelligent.shelves.serial.ProtocolConstants.TEMPERATURE_FIELD_LEN
 import com.shuwei.intelligent.shelves.utils.binaryToHex
 import com.shuwei.intelligent.shelves.utils.hexToBinary
@@ -122,7 +119,7 @@ class SerialProtocolHandler(private val callback: Callback) {
     private fun handleDeviceStatus(data: String, cmdFlag: String) {
         callback.onLog("收到[获取设备状态]${cmdFlag}指令:${data}")
         val weightStartIndex = DEVICE_STATUS_WEIGHT_OFFSET
-        val weightEndIndex = weightStartIndex + SHELF_SENSOR_COUNT * BYTES_PER_WEIGHT
+        val weightEndIndex = weightStartIndex + ProtocolConstants.shelfSensorCount() * BYTES_PER_WEIGHT
         val temperatureEndIndex = weightEndIndex + TEMPERATURE_FIELD_LEN
         try {
             parseWeightData(start = weightStartIndex, end = weightEndIndex, data = data)
@@ -178,11 +175,11 @@ class SerialProtocolHandler(private val callback: Callback) {
      */
     private fun parseHeartbeatData(data: String) {
         runCatching {
-            if (data.length < HEARTBEAT_MIN_LENGTH) return
+            if (data.length < ProtocolConstants.heartbeatMinLength()) return
             val weightStartIndex = HEARTBEAT_WEIGHT_OFFSET
-            val weightEndIndex = weightStartIndex + SHELF_SENSOR_COUNT * BYTES_PER_WEIGHT
+            val weightEndIndex = weightStartIndex + ProtocolConstants.shelfSensorCount() * BYTES_PER_WEIGHT
             parseWeightData(start = weightStartIndex, end = weightEndIndex, data = data)
-            val temperatureEndIndex = HEARTBEAT_TEMPERATURE_START + TEMPERATURE_FIELD_LEN
+            val temperatureEndIndex = ProtocolConstants.heartbeatTemperatureStart() + TEMPERATURE_FIELD_LEN
             parseFixDataBody(data, temperatureEndIndex)
         }.onFailure { it.printStackTrace() }
     }
@@ -212,7 +209,11 @@ class SerialProtocolHandler(private val callback: Callback) {
                 firstByteBinary = "0${firstByteBinary.substring(1)}"
                 val firstByteHex = binaryToHex(firstByteBinary)
                 weightHex = firstByteHex + weightHex.substring(2)
-                -1 * (weightHex.toLongOrNull(16)?.toInt() ?: 0)
+                //-1 * (weightHex.toLongOrNull(16)?.toInt() ?: 0)
+                // 直接用 Long 解析，然后减去 2^32 得到有符号值
+                val unsigned = weightHex.toLongOrNull(16) ?: 0L
+                val signed = if (unsigned >= 0x80000000L) unsigned - 0x100000000L else unsigned
+                signed.toInt()
             }
             callback.onWeightUpdated(index, realWeight)
             count += BYTES_PER_WEIGHT