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#include <SPI.h> | |
#include <SD.h> | |
// Set the pins used | |
#define cardSelect 4 | |
File logfile; | |
// blink out an error code | |
void error(uint8_t errno) { | |
while(1) { | |
uint8_t i; | |
for (i=0; i<errno; i++) { | |
digitalWrite(13, HIGH); | |
delay(100); | |
digitalWrite(13, LOW); | |
delay(100); | |
} | |
for (i=errno; i<10; i++) { | |
delay(200); | |
} | |
} | |
} | |
// This line is not needed if you have Adafruit SAMD board package 1.6.2+ | |
// #define Serial SerialUSB | |
void setup() { | |
// connect at 115200 so we can read the GPS fast enough and echo without dropping chars | |
// also spit it out | |
Serial.begin(115200); | |
Serial.println("\r\nAnalog logger test"); | |
pinMode(13, OUTPUT); | |
// see if the card is present and can be initialized: | |
if (!SD.begin(cardSelect)) { | |
Serial.println("Card init. failed!"); | |
error(2); | |
} | |
char filename[15]; | |
strcpy(filename, "/ANALOG00.TXT"); | |
for (uint8_t i = 0; i < 100; i++) { | |
filename[7] = '0' + i/10; | |
filename[8] = '0' + i%10; | |
// create if does not exist, do not open existing, write, sync after write | |
if (! SD.exists(filename)) { | |
break; | |
} | |
} | |
logfile = SD.open(filename, FILE_WRITE); | |
if( ! logfile ) { | |
Serial.print("Couldnt create "); | |
Serial.println(filename); | |
error(3); | |
} | |
Serial.print("Writing to "); | |
Serial.println(filename); | |
pinMode(13, OUTPUT); | |
pinMode(8, OUTPUT); | |
Serial.println("Ready!"); | |
} | |
uint8_t i=0; | |
void loop() { | |
digitalWrite(8, HIGH); | |
logfile.print("A0 = "); logfile.println(analogRead(0)); | |
Serial.print("A0 = "); Serial.println(analogRead(0)); | |
digitalWrite(8, LOW); | |
delay(100); | |
} |
The sketch still writes incremental filenames, but doesn't write any data to the files.
(I'm using an RTC, would love to be able to write a valid timestamp as well...)
When I add logfile.flush() at the end of my loop, all is well.
I suppose this is the same as putting the Open and Close into the loop, yes?
As per documentation of SD (https://www.arduino.cc/en/Reference/SDCardNotes):
Opening/Closing files
When you use file.write(), it doesn't write to the card until you flush() or close(). Whenever you open a file, be sure to close it to save your data.
The documentation of the "Adafruit Feather M0 Adalogger" needs to be updated, as "https://learn.adafruit.com/adafruit-feather-m0-adalogger/using-the-sd-card" is saying that it writes on the SD-Card once the buffer is full and with this code it will not.
Yeah, had to add logfile.flush()