SPI Flash read/write int

[javiercuellar]

Hi.
I need to store a series of array of integers to flash mem. As far as I know the functions avaliale for these are:
readByte, readBytes, writeByte, writeBytes   

Very basic, so I guess I need to program a way to store integer.
Correct me please please in these pseudocode:

Code Select Expand

for each element of int array  //  ex. {1600,500,1800,300,10,2500}
   read int
   split into 2 byte
   save byte1
   save byte2
end for

Maybe you can point me to an already created example for this.

Thanks

Regards

Javier

[TomWS]

Hi.
I need to store a series of array of integers to flash mem. As far as I know the functions avaliale for these are:
readByte, readBytes, writeByte, writeBytes   

Very basic, so I guess I need to program a way to store integer.
Correct me please please in these pseudocode:

Code Select Expand

for each element of int array  //  ex. {1600,500,1800,300,10,2500}
   read int
   split into 2 byte
   save byte1
   save byte2
end for

Maybe you can point me to an already created example for this.

Thanks

Regards

Javier

You don't need to split the multi-byte value.  If you use writeBytes with the address of the variable (cast as a byte pointer) and the sizeof the object, you can store as many bytes as the size of your object, including an entire array of integers.

Tom
UPDATED: to include array of integer comment.

[javiercuellar]

Excelente Tom!!! Thanks.

Just as example for anyone else. 

Code Select Expand

#include <SPIFlash.h>    //get it here: https://github.com/LowPowerLab/SPIFlash

unsigned int data[] = {8950,4400,700,1550,700,1600,650,450,600,500};
unsigned int data1[100]={};
char input = 0;

#ifdef __AVR_ATmega1284P__
  #define LED           15 // Moteino MEGAs have LEDs on D15
  #define FLASH_SS      23 // and FLASH SS on D23
#else
  #define LED           9 // Moteinos have LEDs on D9
  #define FLASH_SS      8 // and FLASH SS on D8
#endif

SPIFlash flash(FLASH_SS, 0xEF30);

void setup() {
  Serial.begin(9600);
  Serial.print("Start...");

  if (flash.initialize())
    Serial.println("Init OK!");
  else
    Serial.println("Init FAIL!");
  
  delay(1000);

  Serial.print("DataSize: ");
  Serial.println(sizeof(data));

  Serial.println("Input:");
  Serial.println("d: to dump all values from 0 to 4100 bytes");
  Serial.println("e: to erase the whole flash");
  Serial.println("b: to erase 1 block (4096 bytes:");
  Serial.println("1: to save values into flash");
  Serial.println("2: to read values from flash and dump them to serial");  
}

void loop() {
  if (Serial.available() > 0) {
    input = Serial.read();
    int counter = 0;  
    switch (input){
      case 'd':   // dump a little more than 4Kb
        Serial.println("Flash content:");        
        while(counter<=4100){
          Serial.print(counter);
          Serial.print(": ");
          Serial.println(flash.readByte(counter++), DEC);         
        }      
        break;
        
      case 'e':   //erase whole data 
        Serial.print("Erasing Flash chip ... ");
        flash.chipErase();
        while(flash.busy());
        Serial.println("DONE");
        break;

      case 'b':  // erase 1 block  (4K)
        Serial.println("Erasing 4K from position 1");
        flash.blockErase4K(1);
        break;
            
      case '1':  // Save to flash, from position 1 the int array in data
         Serial.println("Saving...");
           flash.writeBytes(1, &data,sizeof(data));              
         Serial.println("Done");
         break;     
         
      case '2':  // Reads from position 1, into array data1, 
         Serial.println("Reading....");
           flash.readBytes(1, data1, sizeof(data));       
           for (int i=0; i<sizeof(data1);i++)
           {
            Serial.print(i);
            Serial.print(": ");
            Serial.println(data1[i]);       
           }
         Serial.println("Done");
         break;
       }
    } 
}