EEPROM_24C08_SWI2C Library

This library interfaces with the 24C08 external I2C 8Kx1 EEPROM. It uses a software I2C implementation, and can therefore use any 2 I/O pins for interfacing with the EEPROM. It only provides simple 1-byte read and write commands. It does not currently support sequential reads or writes.

The library uses the "Polling on ACK" method described in section 5.1.3 of the datasheet to check if the chip has completed a previous write cycle, and therefore does not have any hardcoded delays.

This library depends on a specific SWI2C library.

Usage

Be sure to review the example sketch included with the library.

First, include the library header file:

#include <EEPROM_24C08_SWI2C.h>

Note that this library depends on the SWI2C library.

Next, instantiate an EEPROM_24C08_SWI2C object:

EEPROM_24C08_SWI2C eep(uint8_t sda_pin, uint8_t scl_pin, uint8_t device_address);

If using a separate I/O pin to control WC (Write Control) on the EEPROM, then use the following constructor:

EEPROM_24C08_SWI2C eep(uint8_t sda_pin, uint8_t scl_pin, uint8_t device_address, uint8_t wc_pin);

sda_pin is the pin number for the SDA signal, scl_pin is the pin number for the SCL signal, and wc_pin is the pin number for the WC signal (if used).

device_address is the 7-bit I2C address for memory address 0x0000 of the EEPROM. This is typically 0x50 for 24C08, but may be 0x54 if the E2 signal is pulled high on the EEPROM chip.

Then initialize the object (typically within setup()):

eep.begin();

Remember to use pullup resistors on the SDA and SCL lines.

Library Methods

void write(int address, byte data);

int writeAndVerify(int address, byte data); // Returns 0 if write successful, 1 if unsuccessful

byte read(int address);

References

• SWI2C library
• 24C08 datasheet

License

The software and other files in this repository are released under what is commonly called the MIT License. See the file LICENSE in this repository.