add Unit exmaple sketch comment

Author: Gitshaoxiang

examples/Unit/ACCEL/ACCEL.ino

@@ -1,9 +1,8 @@
 /*
     Description: Read ACCEL Unit three-axis acceleration
-    Please install libraries before compiling: 
+    Please install library before compiling:  
     Arduino-ADXL345: https://github.com/jakalada/Arduino-ADXL345
 */
-
 #include <M5Stack.h>
 #include <ADXL345.h>
 ADXL345 accel(ADXL345_ALT);

examples/Unit/ADC/ADC.ino

@@ -1,5 +1,5 @@
 /*
-    Description: Use ADC Unit to convert 0 ~ 12V analog voltage into 16-bit digital quantity
+    Description: Use ADC Unit to convert 0 ~ 12V analog voltage into 16-bit data and display it on the screen.
 */
 #include <M5Stack.h>
 #include <Wire.h>

examples/Unit/ANGLE/ANGLE.ino

@@ -1,5 +1,5 @@
 /*
-    Description: Read ANGLE Unit input analog quantity, and convert to 12-bit digital quantity for display
+    Description: Read ANGLE Unit input analog quantity, and convert to 12-bit digital quantity for display 
 */
 
 #include <M5Stack.h>

examples/Unit/BUTTON/BUTTON.ino

@@ -1,3 +1,6 @@
+/*
+    Description: Read the button status of BUTTON Unit and display it on the screen
+*/
 #include <M5Stack.h>
 
 int last_value = 0;

examples/Unit/CATEAR/CATEAR.ino

@@ -1,7 +1,8 @@
 /*
-    Please install FastLED library first.
-    In arduino library manage search FastLED
- */
+    Description: Control CAT EAR to run rainbow light show
+    Please install library before compiling:  
+    FastLED: https://github.com/FastLED/FastLED
+*/
 #include <M5Stack.h>
 #include "FastLED.h"
 

examples/Unit/COLOR/COLOR.ino

@@ -1,10 +1,8 @@
 /*
-  Color test
-    hardware: M5Stack
-  
-  please install the Adfruit TCS34725 library first ...
+    Description: Use COLOR Unit to read C, R, G, B values and serial print output.
+    Please install library before compiling:  
+    Adafruit TCS34725: https://github.com/adafruit/Adafruit_TCS34725
 */
-
 #include <Wire.h>
 #include <M5Stack.h>
 #include "Adafruit_TCS34725.h"

examples/Unit/CardKB/CardKB.ino

@@ -1,3 +1,6 @@
+/*
+    Description: Read the characters entered by CardKB Unit and display them on the screen.
+*/
 #include <Wire.h>
 #include <M5Stack.h>
 

examples/Unit/DAC/DAC.ino

@@ -1,8 +1,9 @@
 /*
-    hardware : m5stack uint dac
-
-    please install adafruit MCP4725 lib
+    Description: Use DAC Unit DAC to output 0 ~ 3.3V voltage with an accuracy of 12 bits.
+    Please install library before compiling:  
+    Adafruit MCP4725: https://github.com/adafruit/Adafruit_MCP4725
 */
+
 #include <Wire.h>
 #include <Adafruit_MCP4725.h>
 #include <M5Stack.h>

examples/Unit/DUAL_BUTTON/DUAL_BUTTON.ino

@@ -1,5 +1,5 @@
 /*
-  This Unit connects to GRVOE B on M5Core.
+    Description: Read the button status of DUAL BUTTON Unit and display it on the screen.
 */
 #include <M5Stack.h>
 

examples/Unit/EARTH/EARTH.ino

@@ -1,3 +1,6 @@
+/*
+    Description: Read the analog quantity and digital quantity returned by the EARTH unit, and convert the analog quantity into 12-bit data and display it on the screen.
+*/
 #include <M5Stack.h>
 
 void setup() {