关于pcf8574t的使用

#define DEVICE_1 B0100000

void ()
{
    Wire.begin();
    Serial.begin(9600);
}

void loop()
{
      delay(50);
      Serial.println( IORead(DEVICE_1));
}

void IOWrite(byte address, byte _data ) 
{
 Wire.beginTransmission(address);
 Wire.write(_data);
 Wire.endTransmission(); 
}

byte IORead(int address) 
{
 byte _data;
 Wire.requestFrom(address, 2);
 if(Wire.available()) {
   _data = Wire.read();
 }
 return _data;
}//读