I added another example to my sd card class.
This is a program to check every byte on the sd card.
/* Connect sd card as shown in circuit diagram.
Copy SDCARD folder into arduino-0017/hardware/libraries.
This code will write/read directly to a sector on the sd card
sector number 0 to about 1980000 for a 1.0GB card.
This program writes 199 to every byte on the sd card.
It will only stop when it gets read/write or memory error.
We hope that is after the very last byte of the sd card.
*/
#include <SDCARD.h>
volatile unsigned char buffer[512] ; // this 512 bytes read from or written to sd card
unsigned long sector = 0; // the sector we will write or read from
int error = 0; //the error will be 0 if the sd card works
unsigned long errormillis = 0; // the time when error occured
void setup() // run once, when the sketch starts
{
Serial.begin(9600); // initialize serial communication with computer
}
void loop() // run over and over again
{
for (sector=0; sector<4000000 ; sector++)
{
int i = 0; //general purpose counter
for(i=0;i<512;i++)
buffer[i]=199; //fill the buffer with a number between 0 and 255
error = SDCARD.writeblock(sector); //write the buffer to this sector on the sd card
if (error != 0)
errormillis = millis(); //remember the time had error
while (error !=0) //we stay in this loop
{
Serial.print("sd card write error... code = ");
Serial.println(error);
Serial.print("write error at sector= ");
Serial.println(sector);
sendtime();
delay(1000); //send every second
}//end of if we have an error
i = 0; //general purpose counter
for(i=0;i<512;i++)
buffer[i]=0; //clear the buffer
error = SDCARD.readblock(sector); //read into the buffer this sector in sd card
if (error != 0)
errormillis = millis(); //remember the time had error
while (error !=0) //we stay in this loop
{
Serial.print("sd card read error... code = ");
Serial.println(error);
Serial.print("read error at sector= ");
Serial.println(sector);
sendtime();
delay(1000); //send every second
}//end of if we have an error
for(i=0; i<512; i++) //read 512 bytes
{
if (buffer[i] != 199)
errormillis = millis(); //remember the time had error
while (buffer[i] != 199) //we stay in this loop
{
Serial.print("memory error at byte = ");
Serial.println(i);
Serial.print("memory error at sector= ");
Serial.println(sector);
sendtime();
delay(1000); //send every second
}//end of we have a memory error
}//end of read 512 bytes
if (sector % 100 ==0)
{
errormillis = millis(); //remember the time
Serial.print("we have no errors up to sector = ");
Serial.println(sector);
sendtime();
}//end of ever 10 sectors
}//end of 4000000 sectors done
}//end of loop
void sendtime()
{
Serial.print("elapsed time hours= ");
Serial.print(errormillis/3600000);
Serial.print(" elapsed time minutes= ");
Serial.print((errormillis/60000) % 60);
Serial.print(" elapsed time seconds= ");
Serial.println((errormillis/1000) % 60);
}//end of send the time
My 1.0GB sd card had its first error at sector 1984000.
That is after 1,015,808,000 bytes which must be the highest
number of bytes available on the card.
Each read or write takes 44 msec on the Arduino 2009.
The full program run took 49 hours and 24 minutes.
This is 89 msec for each write, read and check.
If anyone has tried my sd card class, some feedback would be appreciated.
