测试ok

src/log.cpp

@@ -39,7 +39,7 @@ void write_log(String path,unsigned char level,String write_data)
     }
 
     File file;
-      file = SD_MMC.open(path,"a+");
+      file = SD_MMC.open(path,"ab+");
       file.println(write_data);
       file.flush();
       file.close();