Arduino EEPROM读写实例

Posted 2021-09-08 perseverance52

Arduino EEPROM读写实例

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读写函数

• EEPROM.write();//按字节写入
• EEPROM.read();//按字节读
• EEPROM.put();//按数据类型写入
• EEPROM.get();//按数据类型读取
• EEPROM.commit();//提交保存
• EEPROM.end();//提交保存

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读写实例

#include <EEPROM.h>

void setup() {
  Serial.begin(115200);
  EEPROM.begin(32);  //EEPROM.begin(Size)
  // 使用ESP8266 EEPROM不同于标准的Arduino EEPROM类。
  // 在开始读或写之前，需要调用EEPROM.begin(size)，其中size参数是要使用的存储字节数
  // 大小可以是最小4字节到最大4096字节之间的任何位置.
}

void loop() {
  // 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // 32-bytes of random data
  // EEPROM.put(eeAddress, variable_name);    // Writes a variable type e.g. float = 4-bytes, int = 4-bytes, boolean = 1 byte
  // EEPROM.get(eeAddress, variable_name);    // Reads a variable type  e.g. float = 4-bytes, int = 4-bytes, boolean = 1 byte
  // int value = EEPROM.read(eeAddress);      // Read a single byte
  // EEPROM.write(eeAddress, variable_name);  // Write a single byte
  // EEEPROM.commit() commands such as EEPROM.write or EEPROM.put do not write to flash immediately, to invoke them you must call EEPROM.commit() to save changes to flash/EEPROM.
  // EEPROM.end() will also commit, but releases the RAM copy of EEPROM contents.
 
  // Commands to determine variable sizes, needed for storing to EEPROM
  Serial.println("            Floating point variables need: "+String(sizeof(float))+" Bytes");  // 确定需要多少字节(4)来保存一个浮点变量
  Serial.println("Double size floating point variables need: "+String(sizeof(double))+ " Bytes"); // 确定需要多少字节(8)来保存一个浮点变量
  Serial.println("                   Integer variables need: "+String(sizeof(int))+" Bytes");    // 确定需要多少字节(4)来保存一个整数变量
  Serial.println("         Boolean values or variables need: "+String(sizeof(bool))+" Bytes");   // 确定需要多少字节(1)来保存一个布尔变量
  Serial.println("           String variables need at least: "+String(sizeof(String))+" Bytes"); // 确定需要多少字节(最少12)来保存一个字符串变量
  Serial.println();
  
  //----------------------------------------------------------------------------  
  // Example-1 Write a value to EEPROM at address = 0
  int EEaddress = 0;
  EEPROM.write(EEaddress,123); // 将值123写入EEPROM
  // 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 //  EEPROM的内容
  // 7B 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of RAM copy of EEPROM 从RAM拷贝到EEPROM
  EEPROM.commit();
  // 7B 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // EEPROM的内容
  Serial.print("EEPROM contents at Address=0 is  : ");
  Serial.println(EEPROM.read(EEaddress));
  
  //----------------------------------------------------------------------------  
  // Example-2 Write a value to EEPROM at address = 0
  // 7B 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of EEPROM
  EEPROM.write(EEaddress,257); // 将值257写入EEPROM
  EEPROM.commit();
  // 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of EEPROM
  Serial.print("EEPROM contents at Address=0 is  : ");
  Serial.println(EEPROM.read(EEaddress));
  
  //----------------------------------------------------------------------------  
  // Example-3 Write an integer variable to EEPROM at address = 0
  int integer_variable = 257;
  // 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of EEPROM
  EEPROM.put(EEaddress,integer_variable); // 将值257写入EEPROM
  EEPROM.commit();
  // 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of EEPROM
  Serial.print("EEPROM contents at Address=0 is  : ");
  integer_variable = 0; // 证明它是从EEPROM读取的!
  EEPROM.get(EEaddress,integer_variable);
  Serial.println(integer_variable);
  
  //----------------------------------------------------------------------------  
  // Example-4 Write another integer variable to EEPROM
  int integer_variable2 = 1234;
  // 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of EEPROM
  EEaddress = EEaddress + sizeof(int); // 将地址向前移动4
  EEPROM.put(EEaddress,integer_variable2); // 将值1234写入EEPROM
  EEPROM.commit();
  // 01 01 00 00 D2 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // Contents of EEPROM
  Serial.print("EEPROM contents at Address=4 is  : ");
  integer_variable2 = 0; // To prove it read from EEPROM!
  EEPROM.get(EEaddress,integer_variable2);
  Serial.println(integer_variable2);
  EEaddress = EEaddress + sizeof(int); // Moves the address along by 4
 
  //----------------------------------------------------------------------------  
  // Example-5 Write a floating point variable to EEPROM
  float floatingpoint_variable = 3.141592654;
  EEPROM.put(EEaddress,floatingpoint_variable); // Writes the value 3.141592654 to EEPROM
  EEPROM.commit();
  Serial.print("EEPROM contents at Address=8 is  : ");
  floatingpoint_variable = 0; // To prove it read from EEPROM!
  EEPROM.get(EEaddress,floatingpoint_variable);
  Serial.println(floatingpoint_variable,8);//0.00000000
  EEaddress = EEaddress + sizeof(float);        // 将地址向前移动4

  //----------------------------------------------------------------------------  
  // Example-6 Write a string variable to EEPROM
  String string_variable = "Hello world";
  EEPROM.put(EEaddress,string_variable); // Writes the value 3.141592654 to EEPROM
  EEPROM.commit();
  Serial.print("EEPROM contents at Address=12 is : ");
  floatingpoint_variable = 0; // To prove it read from EEPROM!
  EEPROM.get(EEaddress,string_variable);
  Serial.println(string_variable);//Hello world
  EEaddress = EEaddress + sizeof(string_variable);        // Moves the address along by 4

  //----------------------------------------------------------------------------  
  // Example-7 Write a series of values to EEPROM
  for (int i = 1000; i <= 1032; i = i + 4) {
    EEPROM.put(i-1000,i); // Address range 0-32
  }
  EEPROM.commit();
  for (int j = 1000; j <= 1032; j = j + 4) {
    EEPROM.get((j-1000),integer_variable); // Read the 32 values
    Serial.println(integer_variable);
  }

  //----------------------------------------------------------------------------  
  // Example-8 Testing that the EEPROM extent has not been exceeded, remember not to exceed address space
  if (EEaddress == 32) {
    EEaddress = 0;
  }

  //----------------------------------------------------------------------------  
  // Example-9 Compact method of writing and reading values from EEPROM
  EEaddress = 20;
  // Writing写
  floatingpoint_variable = 2 * PI;
  EEaddress += EEPROM.put(EEaddress, floatingpoint_variable);
  integer_variable = 123456789;
  EEaddress += EEPROM.put(EEaddress, integer_variable);
  EEPROM.end();

  EEaddress = 20;
  // Reading读
  EEaddress += EEPROM.get(EEaddress, floatingpoint_variable);
  EEaddress += EEPROM.get(EEaddress, integer_variable);
  Serial.println(floatingpoint_variable,7);//打印浮点数，精度到点后7位；6.2831855
  Serial.println(integer_variable);//123456789

  delay(200000);
}

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• 串口打印
  
• 一个循环周期后，读取的数据