Qdeathstar:
Thanks for your answer.
That seems easy enough for a normal array, but what about a 2D array?
byte data;
if (timerFile = SD.open(“timerData.txt”) {
while ((data = TimerFile.read()) >= 0) {
for (int j = 0; j < 9; j++) {
for (int k = 0; k < 7; k++) {
timerArray[i][j] = data;
}
}
}
}
a byte is defined to be an 8 bit value from 0 … 255. ALWAYS Positive or Greater than or equal to Zero.
So, if(byte>=0) will always be true.
Look at this code:
if (timerFile = SD.open("timerData.txt") {
bool eof=false;
int j=0;
int k=0;
while(!eof){ // until file is empty
int data = TimerFile.read(); // get next byte
eof = data < 0; // is the file empty!
if (!eof) { // save the data into the array
timerArray[j][k] = data; // actually store the byte
k++;
if(k>6) { // filled a row of the array
j++; // increment to next row.
k=0; // start back at the first column element of the next array row.
}
if(j>8) { //the whole array has been filled
break; // exit from the while Loop
}
}
else {// end of file detected, abort loop
break;
}
}
if(eof) {// badness happend, the file was short!
Serial.println(" the file was not as long as expected!");
char buf[100]; // a character (string) buffer I will used to make an error message
sprintf(buf,"The file only had %d bytes in it",((j*6)+k)-1);
Serial.println(buf);
if (k>0) k--; // calculate last filled element
else {
if(j>0) { // ended on last element of prior row
k=6;
j--;
}
}
// now, j and k point to the last filled element
sprintf(buf,"So, the last element was timerArray[%d,%d], and it contains %d.",j,k,timerArray[j][k]);
Serial.println(buf);
}
else Serial.println("Array filled");
}
else Serial.println("could not open file");
Qdeathstar:
byte counter;
if (TimerFile.open(“timerData.txt”)) {
while (TimerFile.read() >= 0 && counter < 63) {
for (int j = 0; j < 9; j++) {
for (int k = 0; k < 7; k++) {
timerArray[j][k] = TimerFile.read();
counter++;
}
}
}
}
TimerFile.close();
}
what is the initial value of counter?
Your code reads a byte (well actually an int), checks to see if that int is greater than or equal to zero, throws the int away, then check if it has done the following 63 times:
Then reads the next 63 bytes [0…8,0…6]. Increments counter, (counter ==1)
Then reads the next 63 bytes [0…8,0…6]. Increments counter, (counter ==2)
Then reads the next 63 bytes [0…8,0…6]. Increments counter, (counter ==3)
Then reads the next 63 bytes [0…8,0…6]. Increments counter, (counter ==4)
Then reads the next 63 bytes [0…8,0…6]. Increments counter, (counter ==5)
Then reads the next 63 bytes [0…8,0…6]. Increments counter, (counter ==6)
… continue this loop until counter reaches 64 or you have read the entire file.
So each time through the loop, you try to read 64 bytes from the file, but you only use 63? Is this what you want?
Qdeathstar:
to not seem to be working, but my method for writing to the file could also be suspect:
if (TimerFile.open("timerData", O_RDWR | O_CREAT | O_AT_END)) {
for (int j = 0; j < 9; j++) {
for (int k = 0; k < 7; k++) {
TimerFile.print(timerArray[j][k]);
}
}
}
TimerFile.close();
}
You do realize that print() makes human readable text from binary data, and write() stores machine readable text?
byte b=100;
print(b); //results in 0x31 0x30 0x30 being stored in the file? (three characters '1' '0' '0')
// While
write(b); // results in 0x64 being stored in the file? (one character 'd')
Chuck.
so that will not work.