 
   lcd.init();
   lcd.clear();
+  
+  if (!SD.begin(SD_CS)) {
+//    Serial.println("initialization failed!");
+    return;
+  }
+//  Serial.println("initialization done.");
+  
+  // open the file. note that only one file can be open at a time,
+  // so you have to close this one before opening another.
+  
 }
 
 void loop(){ 

boolean readGPS() {
    String sub = readLine();
    if(sub.length()) {
      Serial.println(sub);
      Serial.println("-------------------------------------------");
      int split = sub.indexOf(',');    
      String field = sub.substring(0,split);
      if(field.equals(GPRMC)) {


#include "LCD4884.h"

#include <SD.h>

#define GPRMC "$GPRMC" // 推荐最小定位信息
#define GPVTG "$GPVTG" // 地面速度信息
#define GPGGA "$GPGGA" // 获取海拔高度
