Arduino101学习笔记（十四）—— Flash库

Posted 2020-08-19 Blue Mountain

一、一些API

1、打开文件

SerialFlashFile file;
file = SerialFlash.open("filename.bin");
if (file) 
{  // true if the file exists}

 

2、读数据

char buffer[256];
file.read(buffer, 256);

 

3、获取文件尺寸和位置

file.size();
file.position()
file.seek(number);

 

4、写数据

file.write(buffer, 256);

 

5、擦除

file.erase();

     擦除文件，就是将指定文件全部内容写为255 (0xFF)

 

6、创建新文件

SerialFlash.create(filename, size);
SerialFlash.createErasable(filename, size);

      返回值为布尔型，返回True说明创建成功，返回false说明创建失败（没有足够的可用空间）
      创建后，文件大小不可更改。

 

7、删除文件

SerialFlash.remove(filename);

      删除文件后，其暂用的空间不会被回收，但删除后，可以再创建一个同名文件。

 

8、检查文件是否存在（不会打开文件）

SerialFlash.exists(filename);

 

9、列出文件所有信息

SerialFlash.opendir();
SerialFlash.readdir(buffer, buflen, filelen);

 

 

 

二、demo

1、写文件

/*********************头文件**********************/
#include <SerialFlash.h>
#include <SPI.h>

/*********************宏定义*******************/
#define File_SIZE 256

/*********************全局变量*******************/
//文件名和内容（要写的）
const char *filename = "ABDfile.txt";
const char *contents = "0123456789ABCDEF";

//flash指针
const int g_FlashChipSelect = 21; // digital pin for flash chip CS pin

/****************创建文件如果不存在********************/
bool create_if_not_exists (const char *filename) 
{
  if ( !SerialFlash.exists(filename) ) 
  {
    Serial.println("Creating file " + String(filename));
    return (SerialFlash.create(filename, File_SIZE));
  }
 
  Serial.println("File " + String(filename) + " already exists");
  return true;
}


/*****************初始化函数********************/
void setup() 
{
  //串口配置
  Serial.begin(9600);
  while (!Serial) ;
  delay(100);
  Serial.println("Serial is OK!");

  //配置Flash
  if ( !SerialFlash.begin(g_FlashChipSelect) ) 
  {
    Serial.println("Unable to access SPI Flash chip");
  }

  //创建文件指针
  SerialFlashFile file;

  //创建文件，如果这个文件不存在
  if (!create_if_not_exists(filename))
  {
    Serial.println("Not enough space to create file " + String(filename));
    return;
  }
  
}

void loop() 
{

}

2、读文件

/*********************头文件**********************/
#include <SerialFlash.h>
#include <SPI.h>

/*********************宏定义*******************/


/*********************全局变量*******************/
//flash指针
const int g_FlashChipSelect = 21; // digital pin for flash chip CS pin

/********************空格*******************/
void spaces(int num) 
{
  for ( int i=0; i < num; i++ ) 
  {
    Serial.print(" ");
  }
}


/*****************初始化函数********************/
void setup() 
{
  //串口配置
  Serial.begin(9600);
  while (!Serial) ;
  delay(100);
  Serial.println("Serial is OK!");

  //配置Flash
  if ( !SerialFlash.begin(g_FlashChipSelect) ) 
  {
    Serial.println("Unable to access SPI Flash chip");
  }

  //开路径
  SerialFlash.opendir();
  
  while(1)
  {
    char filename[64];
    unsigned long filesize;

    if( SerialFlash.readdir( filename , sizeof(filename) , filesize) )
    {
      Serial.print("   ");
      Serial.print(filename);
      spaces( 20 - strlen(filename) );
      Serial.print("   ");
      Serial.print(filesize);
      Serial.print(" bytes");
      Serial.println();
    }
    else
    {
      break;
      
    }
  }
  
}

void loop() 
{

}

3、删除全部Flash

/*********************头文件**********************/
#include <SerialFlash.h>
#include <SPI.h>

/*********************宏定义*******************/


/*********************全局变量*******************/
//flash指针
const int g_FlashChipSelect = 21; // digital pin for flash chip CS pin

SerialFlashFile file;
const unsigned long testIncrement = 4096;


float eraseBytesPerSecond(const unsigned char *id) 
{
  if (id[0] == 0x20) return 152000.0; // Micron
  if (id[0] == 0x01) return 500000.0; // Spansion
  if (id[0] == 0xEF) return 419430.0; // Winbond
  if (id[0] == 0xC2) return 279620.0; // Macronix
  return 320000.0; // guess?
}
 


/*****************初始化函数********************/
void setup() 
{
  //串口配置
  Serial.begin(9600);
  while (!Serial) ;
  delay(100);
  Serial.println("Serial is OK!");

  // wait up to 10 seconds for Arduino Serial Monitor
  unsigned long startMillis = millis();
  while (!Serial && (millis() - startMillis < 10000)) ;
  delay(100);
  
  //配置Flash
  if ( !SerialFlash.begin(g_FlashChipSelect) ) 
  {
    Serial.println("Unable to access SPI Flash chip");
  }

 //读ID
  unsigned char id[5];
  SerialFlash.readID(id);
  unsigned long size = SerialFlash.capacity(id);
  
  //开路径
  SerialFlash.opendir();

  if( size > 0 )
  {
    Serial.print( "Flash Memory has ");
    Serial.print( size );
    Serial.println( " bytes.");
    Serial.println( "Erasing All Flash Memory:");

    Serial.print("  estimated wait: ");
    int seconds = (float)size / eraseBytesPerSecond(id) + 0.5;
    Serial.print(seconds);
    Serial.println(" seconds.");
    Serial.println("  Yes, full chip erase is SLOW!");
    SerialFlash.eraseAll();

    unsigned long dotMillis = millis();
    unsigned char dotcount = 0;
    while (SerialFlash.ready() == false) 
    {
      if (millis() - dotMillis > 1000) 
      {
        dotMillis = dotMillis + 1000;
        Serial.print(".");
        dotcount = dotcount + 1;
        if (dotcount >= 60) 
        {
          Serial.println();
          dotcount = 0;
        }
      }
    }
    if (dotcount > 0)  Serial.println();
    Serial.println("Erase completed");
    unsigned long elapsed = millis() - startMillis;
    Serial.print("  actual wait: ");
    Serial.print(elapsed / 1000ul);
    Serial.println(" seconds.");
  }
  
}

void loop() 
{

}