Electrically Erasable Programmable Read-Only Memory (EEPROM) is a type of non-volatile memory that can be read, written, and erased multiple times. It is commonly used in embedded systems to store persistent data that needs to be retained even when the system is powered off.
EEPROM Characteristics
- Non-Volatile: Data stored in EEPROM is retained even when the power supply is removed.
- Rewritable: EEPROM can be erased and programmed multiple times.
- Slow Write Speed: Compared to other types of memory, EEPROM has a relatively slow write speed.
- Limited Write Cycles: EEPROM has a limited number of write cycles, typically around 100,000.
EEPROM Usage in Embedded Systems
EEPROM is widely used in embedded systems for various purposes, including:
- Configuration Settings: Storing user preferences, system settings, and calibration data.
- Data Logging: Recording sensor measurements or other data for later analysis.
- Firmware Updates: Storing firmware updates that can be downloaded and installed remotely.
- Security: Storing encryption keys, passwords, or other sensitive information.
Interfacing EEPROM with Arduino
Arduino boards often have built-in EEPROM or can be connected to external EEPROM modules. The specific interface and commands will vary depending on the EEPROM type and Arduino board.
Example: Using Arduino’s Built-in EEPROM
C++
#include <EEPROM.h>
const int eepromAddress = 0; // Address where data will be stored
void setup() {
Serial.begin(9600);
}
void loop() {
// Write data to EEPROM
EEPROM.write(eepromAddress, 123);
// Read data from EEPROM
int data = EEPROM.read(eepromAddress);
Serial.println(data);
}
Key Considerations
- EEPROM Size: The size of the EEPROM determines the amount of data that can be stored.
- Write Cycles: Be mindful of the limited write cycles of EEPROM. Avoid excessive writes to prolong its lifespan.
- Data Corruption: EEPROM can be susceptible to data corruption due to factors like power supply fluctuations or radiation. Implement error-checking mechanisms to mitigate this risk.
- External EEPROM Modules: If your Arduino board doesn’t have built-in EEPROM, you can connect an external EEPROM module using the appropriate interface (e.g., I2C, SPI).
By understanding the basics of EEPROM and its applications, you can effectively use it in your Arduino projects to store persistent data and enhance system functionality.
