ardupilot/libraries/DataFlash/examples/DataFlash_test/DataFlash_test.pde

/*
	Example of DataFlash library.
	Code by Jordi MuÒoz and Jose Julio. DIYDrones.com
*/

// Libraries
#include <SPI.h>			// Arduino SPI lib
#include <DataFlash.h>

#define HEAD_BYTE1 0xA3
#define HEAD_BYTE2 0x95

// NOTE:  You must uncomment one of the following two lines
DataFlash_APM2 	DataFlash;			// Uncomment this line if using APM2 hardware
//DataFlash_APM1	DataFlash;			// Uncomment this line if using APM1 hardware


void setup()
{
	Serial.begin(115200);
	DataFlash.Init();			 // DataFlash initialization
	
	Serial.println("Dataflash Log Test 1.0");

	// Test
	delay(20);
	DataFlash.ReadManufacturerID();
	delay(10);
	Serial.print("Manufacturer:");
	Serial.print(int(DataFlash.df_manufacturer));
	Serial.print(",");
	Serial.print(DataFlash.df_device);
	Serial.println();
	
	// We start to write some info (sequentialy) starting from page 1
	// This is similar to what we will do...
	DataFlash.StartWrite(1);
	Serial.println("After testing perform erase before using DataFlash for logging!");
	Serial.println("");
	Serial.println("Writing to flash... wait...");
	for (int i = 0; i < 1000; i++){	 // Write 1000 packets...
		// We write packets of binary data... (without worry about nothing more)
		DataFlash.WriteByte(HEAD_BYTE1);
		DataFlash.WriteByte(HEAD_BYTE2);
		DataFlash.WriteInt(2000 + i);
		DataFlash.WriteInt(2001 + i);
		DataFlash.WriteInt(2002 + i);
		DataFlash.WriteInt(2003 + i);
		DataFlash.WriteLong((long)i * 5000);
		DataFlash.WriteLong((long)i * 16268);
		DataFlash.WriteByte(0xA2);	 // 2 bytes of checksum (example)
		DataFlash.WriteByte(0x4E);
		delay(10);
		}
	delay(100);
}

void loop()
{
	int 	i, tmp_int;
	byte 	tmp_byte1, tmp_byte2;
	long 	tmp_long;
	
	Serial.println("Start reading page 1...");

	DataFlash.StartRead(1);	 // We start reading from page 1

	for (i = 0; i < 200; i++){	 // Read 200 packets...
		
		tmp_byte1 = DataFlash.ReadByte();
		tmp_byte2 = DataFlash.ReadByte();
		
		Serial.print("PACKET:");
		
		if ((tmp_byte1 == HEAD_BYTE1) && (tmp_byte1 == HEAD_BYTE1)){
			// Read 4 ints...
			tmp_int = DataFlash.ReadInt();
			Serial.print(tmp_int);
			Serial.print(",");
			tmp_int = DataFlash.ReadInt();
			Serial.print(tmp_int);
			Serial.print(",");
			tmp_int = DataFlash.ReadInt();
			Serial.print(tmp_int);
			Serial.print(",");
			tmp_int = DataFlash.ReadInt();
			Serial.print(tmp_int);
			Serial.print(",");
			
			// Read 2 longs...
			tmp_long = DataFlash.ReadLong();
			Serial.print(tmp_long);
			Serial.print(",");
			tmp_long = DataFlash.ReadLong();
			Serial.print(tmp_long);
			Serial.print(";");
			
			// Read the checksum... 
			tmp_byte1 = DataFlash.ReadByte();
			tmp_byte2 = DataFlash.ReadByte();
		}		
		Serial.println();
	}
	Serial.println("");
	Serial.println("Test complete.  Test will repeat in 20 seconds");
	Serial.println("");
	delay(20000);
}