SOURCE

//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;  
}  
console.log(UnicodeToUtf8([0,61,87]))