EEPROM (Electrically Erasable Programmable Read-Only Memory)，电可擦可编程只读存储器--一种掉电后数据不丢失的存储芯片。简而言之就是你想断电后arduino还要保存一些参数，就使用EEPROM吧。在各型号的arduino控制器上的AVR芯片均带有EEPROM，也有外接的EEPROM芯片，常见arduino控制器的EEPROM大小：Arduino UNO、Arduino duemilanove-m328、Zduino m328均使用ATmega328芯片，EEPROM都为1KArduino duemilanove-m168的EEPROM为512bytesArduino 2560的EEPROM为4K下面我们介绍arduino自带的EEPROM使用方法，arduino的库已经为我们准备好了EEPROM类库，我们要使用得先调用EEPROM.h，然后使用write和read方法，即可操作EEPROM。
另：下面的官方例子由于写成较早，所以讲EEPROM的大小都定为了512字节，实际使用中，大家可参照上面所说的EEPROM大小，自行更改。
1.写入
选择 File>Examples>EEPROM>eeprom_write
代码语言：javascript复制 /*
* EEPROM Write
*
* Stores values read from analog input 0 into the EEPROM.
* These values will stay in the EEPROM when the board is
* turned off and may be retrieved later by another sketch.
*/
#include <EEPROM.h>
// EEPROM 的当前地址,即你将要写入的地址,这里就是从0开始写
int addr = 0;
void setup()
{
}
void loop()
{
//模拟值读出后是一个0-1024的值，但每字节的大小为0-255，所以这里将值除以4再存储到val
int val = analogRead(0) / 4;
// write the value to the appropriate byte of the EEPROM.
// these values will remain there when the board is
// turned off.
EEPROM.write(addr, val);
// advance to the next address. there are 512 bytes in
// the EEPROM, so go back to 0 when we hit 512.
addr = addr 1;
if (addr == 512)
addr = 0;
delay(100);
}2.读取
选择 File>Examples>EEPROM>eeprom_read
代码语言：javascript复制 /*
* EEPROM Read
*
* Reads the value of each byte of the EEPROM and prints it
* to the computer.
* This example code is in the public domain.
*/
#include <EEPROM.h>
// start reading from the first byte (address 0) of the EEPROM
int address = 0;
byte value;
void setup()
{
// initialize serial and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}
}
void loop()
{
// read a byte from the current address of the EEPROM
value = EEPROM.read(address);
Serial.print(address);
Serial.print("t");
Serial.print(value, DEC);
Serial.println();
// advance to the next address of the EEPROM
address = address 1;
// there are only 512 bytes of EEPROM, from 0 to 511, so if we're
// on address 512, wrap around to address 0
if (address == 512)
address = 0;
delay(500);
}3.清除
选择 File>Examples>EEPROM>eeprom_clear清除EEPROM的内容，其实就是把EEPROM中每一个字节写入0，因为只用清一次零，所以整个程序都在setup部分完成。
代码语言：javascript复制 /* * EEPROM Clear
*
* Sets all of the bytes of the EEPROM to 0.
* This example code is in the public domain.
*/
#include <EEPROM.h>
void setup()
{
// 让EEPROM的512字节内容全部清零
for (int i = 0; i < 512; i )
EEPROM.write(i, 0);
// 清零工作完成后，将L灯点亮，提示EEPROM清零完成
digitalWrite(13, HIGH);
}
void loop()
{
}
