diff --git a/examples/Unit/PIR/pir.ino b/examples/Unit/PIR/pir.ino
index b7c5166..d7aeb7d 100644
--- a/examples/Unit/PIR/pir.ino
+++ b/examples/Unit/PIR/pir.ino
@@ -1,44 +1,39 @@
 /*
-    Description: Human body detection using PIR Unit.
+*******************************************************************************
+* Copyright (c) 2021 by M5Stack
+*                  Equipped with M5Core sample source code
+*                          配套  M5Core 示例源代码
+* Visit the website for more information：https://docs.m5stack.com/en/core/gray
+* 获取更多资料请访问：https://docs.m5stack.com/zh_CN/core/gray
+*
+* describe：PIR.  人体红外
+* date：2021/8/11
+*******************************************************************************
+  Please connect to Port B(26、36),Human body detection using PIR Unit.
+  请连接端口B(26、36),使用PIR Unit进行人体检测。
 */
+
 #include <M5Stack.h>
 
 void setup() {
-  M5.begin();
-  M5.Power.begin();
-
-  Serial.begin(115200);
-  M5.Lcd.clear(BLACK);
-  M5.Lcd.setTextColor(YELLOW);
-  M5.Lcd.setTextSize(2);
-  M5.Lcd.setTextSize(2);
-  M5.Lcd.setCursor(80, 0); 
+  M5.begin(); //Init M5Stack.  初始化M5Stack
+  M5.Power.begin(); //Init power  初始化电源模块
+  M5.lcd.setTextSize(2);  //Set the text size to 2.  设置文字大小为2
   M5.Lcd.println("PIR example");
-  Serial.println("PIR example: ");
-  M5.Lcd.setCursor(65, 10);
-  M5.Lcd.setTextColor(WHITE);
-  pinMode(36, INPUT);
+  M5.Lcd.setCursor(0, 25);  //Position the cursor at (0,25).  将光标固定在(0,25)
+  M5.Lcd.println("Status: \nValue: ");
+  pinMode(36, INPUT); //Set pin 36 to input mode.  设置36号引脚为输入模式
 }
 
 void loop() {
-  M5.Lcd.setCursor(0,25); M5.Lcd.print("Status: ");
-  M5.Lcd.setCursor(0,45); M5.Lcd.print("Value: ");
-  
-  M5.Lcd.fillRect(95,25,200,25,BLACK);
-  M5.Lcd.fillRect(95,45,200,25,BLACK);
-  
-  if(digitalRead(36)==1){
+  M5.Lcd.fillRect(90,25,180,50,BLACK);  //Draw a black rectangle 180 by 50 at (90,25).  在(90,25)处画一个宽180高50的黑的矩形
+  if(digitalRead(36)==1){ //If pin 36 reads a value of 1.  如果36号引脚的读取到的值为1
     M5.Lcd.setCursor(95, 25);M5.Lcd.print("Sensing");
     M5.Lcd.setCursor(95, 45);M5.Lcd.print("1");
-    Serial.println("PIR Status: Sensing");
-    Serial.println(" value: 1");
   }
   else{
     M5.Lcd.setCursor(95, 25);M5.Lcd.print("Not Sensed");
     M5.Lcd.setCursor(95, 45);M5.Lcd.print("0");
-    Serial.println("PIR Status: Not Sensed");
-    Serial.println(" value: 0");
   }
   delay(500);
-  M5.update();
-}
+}
\ No newline at end of file