diff --git a/app/src/main/java/com/yinuo/safetywatcher/watcher/port/cmd/CalibrationCmd.kt b/app/src/main/java/com/yinuo/safetywatcher/watcher/port/cmd/CalibrationCmd.kt
new file mode 100644
index 0000000..4adbe76
--- /dev/null
+++ b/app/src/main/java/com/yinuo/safetywatcher/watcher/port/cmd/CalibrationCmd.kt
@@ -0,0 +1,55 @@
+package com.yinuo.safetywatcher.watcher.port.cmd
+
+/**
+ * 校准命令
+ * @param index 传感器编号 00 01 02 03
+ * @param target 目标值
+ */
+class CalibrationCmd(private val index: Int, private val target: Int) {
+    val ZERO = 0x87.toByte()
+    val SPAN = 0x88.toByte()
+
+    fun buildZeroCmd(): ByteArray {
+        return build(ZERO)
+    }
+
+    fun buildSPANCmd(): ByteArray {
+        return build(SPAN)
+    }
+
+    private fun build(cmd: Byte): ByteArray {
+        var highBit: Byte = 0x00
+        var lowBit: Byte = 0x00
+        if (index != 0) {
+            highBit = (target shr 8 and FF).toByte()
+            lowBit = (target and FF).toByte()
+        }
+        return byteArrayOf(
+            0xFF.toByte(),
+            index.toByte(),
+            cmd,
+            highBit,
+            lowBit,
+            0x00,
+            0x00,
+            0x00
+        ).calibrationSum()
+    }
+}
+
+private fun ByteArray.calibrationSum(): ByteArray {
+    return this.plus(getCheckSum(this))
+}
+
+fun getCheckSum(packet: ByteArray): Byte {
+    var checksum = 0
+    for (i in packet.indices) {
+        if (i in 1..7) {
+            checksum += packet[i]
+        }
+    }
+    checksum = 0xffff - checksum
+    checksum += 1
+    return checksum.toByte()
+}
+