arduino里I2C的主机这个错误是为什么？ 怎么改呀？？

[weixin_40960090]

#include <Wire.h>
const int tiltPin = 2;
const int mgPin = 3;
const int soundPin = A1;
const int waterPin = A3;
void setup() {
Wire.begin();
Serial.begin(9600);
Serial.println("READY");// put your setup code here, to run once:
pinMode(tiltPin, INPUT);
pinMode(mgPin, INPUT);
pinMode(soundPin, INPUT);
pinMode(waterPin, INPUT);
}

void loop() {
int val;
if(Serial.available()>0)
{
val=Serial.read();
if(val==49)
{
Wire.beginTransmission(4);
Wire.write(1);
Wire.endTransmission();
Serial.println("49 OK");
delay(10);
}
else if(val==50)
{
Wire.beginTransmission(4);
Wire.write(2);
Wire.endTransmission();
Serial.println("50 OK");
delay(10);
}
else if(val==51)
{
Wire.beginTransmission(5);
Wire.write(3);
Wire.endTransmission();
Serial.println("51 OK");
delay(10);
}
else if(val==52)
{
Wire.beginTransmission(5);
Wire.write(4);
Wire.endTransmission();
Serial.println("52 OK");
delay(10);
}
else Serial.println(val);
}
}
Serial.print("tiltPin");
Serial.println(digitalRead(tiltPin));
Serial.print("mgPin");
Serial.println(digitalRead(mgPin));
Serial.print("soundPin");
Serial.println(analogRead(soundPin));
Serial.print("waterPin");
Serial.println(analogRead(waterPin));

delay(200);// put your main code here, to run repeatedly:

}

[greex]

编译错误还是运行错误，这个得说下啊