User Manual

9
28. Serial.begin(9600);
29. while (!Serial) {
30. ; // wait for serial port to connect. Needed for native USB port only
31. }
32.
33.
34. Serial.print("Initializing SD card...");
35.
36. if (!SD.begin(4)) {
37. Serial.println("initialization failed!");
38. while (1);
39. }
40. Serial.println("initialization done.");
41.
42. // open the file. note that only one file can be open at a time,
43. // so you have to close this one before opening another.
44. myFile = SD.open("test.txt", FILE_WRITE);
45.
46. // if the file opened okay, write to it:
47. if (myFile) {
48. Serial.print("Writing to test.txt...");
49. myFile.println("testing 1, 2, 3.");
50. // close the file:
51. myFile.close();
52. Serial.println("done.");
53. } else {
54. // if the file didn't open, print an error:
55. Serial.println("error opening test.txt");
56. }
57.
58. // re-open the file for reading:
59. myFile = SD.open("test.txt");
60. if (myFile) {
61. Serial.println("test.txt:");
62.
63. // read from the file until there's nothing else in it:
64. while (myFile.available()) {
65. Serial.write(myFile.read());
66. }
67. // close the file:
68. myFile.close();
69. } else {
70. // if the file didn't open, print an error:
71. Serial.println("error opening test.txt");
72. }
73. }
74.
75. void loop() {
76. // nothing happens after setup
77. }