User Manual

13
85. // print the buffer length. This will change depending on when
86. // data is actually written to the SD card file:
87. Serial.print("Unsaved data buffer length (in bytes): ");
88. Serial.println(buffer.length());
89. // note the time that the last line was added to the string
90. lastMillis = now;
91. }
92.
93. // check if the SD card is available to write data without blocking
94. // and if the buffered data is enough for the full chunk size
95. unsigned int chunkSize = txtFile.availableForWrite();
96. if (chunkSize && buffer.length() >= chunkSize) {
97. // write to file and blink LED
98. digitalWrite(LED_BUILTIN, HIGH);
99. txtFile.write(buffer.c_str(), chunkSize);
100. digitalWrite(LED_BUILTIN, LOW);
101.
102. // remove written data from buffer
103. buffer.remove(0, chunkSize);
104. }
105. }