//unicode为1个接收数据，串口收到的字符编码放在该数组中 
function UnicodeToUtf8(unicode) { 
  var uchar; 
  var utf8str = ""; 
  var i; 
  for(i=0; i<unicode.length;i+=2){      
    uchar = (unicode[i]<<8) | unicode[i+1];        //UNICODE为2字节编码，一次读入2个字节 
    utf8str = utf8str + String.fromCharCode(uchar);  //使用String.fromCharCode强制转换 
  } 
  return utf8str; 
} 
function Utf8ToUnicode(strUtf8) { 
  var i,j; 
  var uCode; 
  var temp = new Array(); 
  for(i=0,j=0; i<strUtf8.length; i++){ 
    uCode = strUtf8.charCodeAt(i); 
    if(uCode<0x100){         //ASCII字符 
      temp[j++] = 0x00; 
      temp[j++] = uCode; 
    }else if(uCode<0x10000){ 
      temp[j++] = (uCode>>8)&0xff; 
      temp[j++] = uCode&0xff; 
    }else if(uCode<0x1000000){ 
      temp[j++] = (uCode>>16)&0xff; 
      temp[j++] = (uCode>>8)&0xff; 
      temp[j++] = uCode&0xff; 
    }else if(uCode<0x100000000){ 
      temp[j++] = (uCode>>24)&0xff; 
      temp[j++] = (uCode>>16)&0xff; 
      temp[j++] = (uCode>>8)&0xff; 
      temp[j++] = uCode&0xff; 
    }else{ 
      break; 
    } 
  } 
  temp.length = j; 
  return temp; 
}