The steering gear follows the sun

wiring:

First, the two light-sensitive resistor in parallel with the resistor in series
to the parallel circuit for 5v DC
arduino A0 \ A1 are connected to two light-sensitive voltage across the resistor (in fact, one end) of
the steering gear red --3.3v
servo black line --GND
servos Yellow wire-signal input (pin 9)

Code:

#include <Servo.h>
//ADC测电压引脚定义
int L_ADC = A0;
int R_ADC = A1;

//舵机变量
Servo myservo;  // 定义Servo对象来控制
int pos = 0;    // 角度存储变量



void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  //analogReference(INTERNAL); //调用板载1.1V基准源
  analogReference(DEFAULT); //调用当前工作电压基准源

  myservo.attach(9);  // 舵机控制线连接数字9
  pos=90;
  myservo.write(pos); // 舵机角度写入

}
 
void loop() {
   while(1) 
  {
    
  // put your main code here, to run repeatedly:
  int V_L = analogRead(L_ADC);    //读取A0口的电压值
  int V_R = analogRead(R_ADC);    //读取A0口的电压值
  //float temp = (1.1 * n * 100.0) / 1024;//初始化时，必须指明电压基准源：analogReference(INTERNAL); //调用板载1.1V基准源
  float L_temp = (5.0 * V_L * 100.0) / 1024;
  float R_temp = (5.0 * V_R * 100.0) / 1024;
  /*
  Serial.print("L_temp=");
  Serial.print(L_temp);
  Serial.print("      R_temp=");
  Serial.println(R_temp);
*/
  

    
  if(L_temp-R_temp>10)
  {
    /*Serial.println("电机右转");   
    
    Serial.print("L_temp=");
    Serial.print(L_temp);
    Serial.print("      R_temp=");
    Serial.println(R_temp);
  */
    if( pos>10)
    {
    pos=pos-1;
    // in steps of 1 degree
    myservo.write(pos); // 舵机角度写入
    }

  }

  
  if(R_temp-L_temp>10)
  {
    /*Serial.println("电机左转"); 
 
    Serial.print("L_temp=");
    Serial.print(L_temp);
    Serial.print("      R_temp=");
    Serial.println(R_temp);
    */
    if( pos<180)
    {
    pos=pos+1;
    // in steps of 1 degree
    myservo.write(pos); // 舵机角度写入
    
    }
  }  
 


  delay(10);
  }

}