Code:
/*
SD card: fprintf_() und fgets_()
ver 1.01
*/
#include <stdarg.h>
#include <stdio.h>
#include <SPI.h>
#include <SD.h>
// SD Card
#define SD_CSpin 4
File myFile;
char fname[64];
char sdata[128];
char sbuf[128];
//*******************************************************************************************
char * fgets_ ( char * str, int32_t num, File * stream ) {
int32_t i = 0;
int16_t chr;
strcpy(str, "");
while (i < (num - 1)) { // got room for newline and terminating null?
chr = stream->read();
if (chr < 0) // end of file
break;
str[i++] = chr;
if ('\n' == chr) // end of line
break;
}
if (i) { // room in buffer for terminating null
str[i] = 0;
return str;
}
else
return NULL; // buffer too small or immediate end of file
// { strcpy(str, ""); return str; } // alternative
}
//*******************************************************************************************
//*******************************************************************************************
int32_t fprintf_ ( File * stream, const char fmtstr[], ... ) {
char str[1024];
va_list arguments;
int16_t num;
va_start( arguments, fmtstr);
num = vsnprintf(str, sizeof str, fmtstr, arguments);
// #debug
// Serial.println( "string to write to file="); Serial.println( str);
stream->print(str);
va_end( arguments );
return num;
}
//*******************************************************************************************
void setup()
{
int16_t p, i, cnt;
float x;
char sval[20];
int16_t ival;
double fval;
pinMode(SD_CSpin, OUTPUT);
Serial.begin(9600);
sprintf(sbuf,"#: SD Initializing... ");
Serial.println(sbuf);
while(!SD.begin(SD_CSpin) ) {
sprintf(sbuf,"#: ...SD init failed ");
Serial.println(sbuf);
delay(1000);
}
sprintf(sbuf,"#: ...SD OK ! ");
Serial.println(sbuf);
strcpy(fname,"test.txt");
if (SD.exists(fname) ) {
sprintf(sbuf,"#: %s exists ",fname);
Serial.println(sbuf);
sprintf(sbuf,"#: Removing %s ",fname);
Serial.println(sbuf);
SD.remove("test.txt");
// removed: success ?
if (SD.exists(fname) ) {
sprintf(sbuf,"#: %s exists ",fname);
Serial.println(sbuf);
}
else {
sprintf(sbuf,"#: %s N/A ",fname);
Serial.println(sbuf);
}
}
// open the file. note that only one file can be open at a time,
// so you have to close this one before opening another.
myFile = SD.open(fname, FILE_WRITE);
if (myFile) {
// if the file opened okay, write to it, then close file:
sprintf(sbuf,"#: Writing strings to %s ",fname);
Serial.println(sbuf);
//---------------------------------------------------------------------------------
// write data to file
fprintf_(&myFile, "%s\n%d\n%d\n%f\n%f\n", "Teststring", 1, 2, PI, 4.567890);
//---------------------------------------------------------------------------------
// close the file:
myFile.close();
sprintf(sbuf,"#: %s closed. ",fname);
Serial.println(sbuf);
}
else {
// if the file didn't open, print an error:
sprintf(sbuf,"#: error opening %s ",fname);
Serial.println(sbuf);
}
Serial.println();
// re-open the file for reading:
myFile = SD.open(fname);
if (myFile) {
sprintf(sbuf,"#: reading %s ",fname);
Serial.println(sbuf);
// read from the file until there's nothing else in it:
i=0;
cnt=1;
while (myFile.available()) {
strcpy(sdata, "");
fgets_ ( sdata, 20, &myFile );
Serial.print(cnt); Serial.print(": string raw="); Serial.println(sdata);
Serial.println("rueckformatiert:");
if (cnt==1) {Serial.print("str ="); Serial.println(sdata); }
if (cnt==2) {Serial.print("int ="); Serial.println(atoi(sdata) ); }
if (cnt==3) {Serial.print("int ="); Serial.println(atoi(sdata) ); }
if (cnt==4) {Serial.print("float="); Serial.println(atof(sdata) ); }
if (cnt==5) {Serial.print("float="); Serial.println(atof(sdata) ); }
++cnt;
}
// close the file:
myFile.close();
sprintf(sbuf,"#: %s closed. ",fname);
Serial.println(sbuf);
} else {
// if the file didn't open, print an error:
sprintf(sbuf,"#: error opening %s ",fname);
Serial.println(sbuf);
}
}
void loop()
{
// nothing happens after setup
}
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