I found this tiny EEPROM from an old random board. Soldered it on copper board to use it as a through-hole component and to use on the breadboard
The EEPROM is 24C02N. It uses i2C to communicate and is relatively easy to read/write. I used Arduino Nano for that.
Some functions I wrote:
#include <Arduino.h>
#include <Wire.h> // TwoWire
// read 0b10100001
// write 0b10100000
const int DEVICE_ADDR = 0b01010000; // 0 + 7bit address
const int MEM_SIZE_BYTES = 256;
/*
Write Byte
*/
void write_byte(int word_addr, uint8_t data) {
Wire.beginTransmission(DEVICE_ADDR);
Wire.write(word_addr);
Wire.write(data);
Wire.endTransmission();
}
/*
Write array to eepromm
*/
void write_array(uint8_t word_addr, int data[], int size) {
Wire.beginTransmission(DEVICE_ADDR);
Wire.write(word_addr);
for (int i = 0; i < size; i++)
{
Wire.write(data[i]);
}
Wire.endTransmission();
}
/*
Random Read Byte
*/
uint8_t read_byte(uint8_t word_addr) {
uint8_t data = 0;
Wire.beginTransmission(DEVICE_ADDR);
Wire.write(word_addr);
Wire.endTransmission();
//delay(1);
Wire.requestFrom(DEVICE_ADDR, 1); // read 1 byte
//delay(1);
if ( Wire.available() ) {
data = Wire.read();
}
return data;
}
/*
Read to array
*/
void read_to_array(int addr, int * array, int size ) {
Wire.beginTransmission(DEVICE_ADDR);
Wire.write(addr);
Wire.endTransmission();
delay(1);
for (int i = 0; i < size; i++) {
Wire.requestFrom(DEVICE_ADDR, 1); // read 1 byte
delay(1);
if ( Wire.available() ) {
array[i] = Wire.read();
}
}
}
/*
Print Memory content
*/
void print_ascii_table() {
int stepp = 16;
int line[stepp];
for (int address = 1; address < MEM_SIZE_BYTES; address += stepp) {
char print_addr[6];
sprintf(print_addr, "%04x ", address);
Serial.print(print_addr);
for (int byte = 0; byte < stepp; byte++)
{
char hex_data[4];
line[byte] = read_byte(address+byte);
sprintf(hex_data, "%02x ", line[byte]);
Serial.print(hex_data);
}
Serial.print(" ");
for (int ascii = 0; ascii < stepp; ascii++) {
Serial.print((char) line[ascii]);
}
Serial.println();
}
}
/*
Print Memory content
*/
void print_char_table() {
int stepp = 16;
int line[stepp];
for (int address = 1; address < MEM_SIZE_BYTES; address += stepp) {
char print_addr[6];
sprintf(print_addr, "%04x ", address);
Serial.print(print_addr);
for (int byte = 0; byte < stepp; byte++) {
char hex_data[4];
line[byte] = read_byte(address+byte);
sprintf(hex_data, "%02x ", line[byte]);
Serial.print(hex_data);
}
Serial.print(" ");
// print char
for (int ascii = 0; ascii < stepp; ascii++) {
if (line[ascii] < 32 || line[ascii] > 126) {
Serial.print(".");
} else {
Serial.print((char) line[ascii]);
}
}
Serial.println();
}
}
void print_binary() {
/*
for (int i = 0; i < 256; i++) // 256 bytes total
{
uint8_t data_byte = read_byte(i);
Serial.print(data_byte, BIN);
Serial.print(" ");
}
*/
int stepp = 8;
int line[stepp];
for (int address = 1; address < MEM_SIZE_BYTES; address += stepp) {
char print_addr[6];
sprintf(print_addr, "%04x ", address);
Serial.print(print_addr);
for (int byte = 0; byte < stepp; byte++) {
//char hex_data[4];
line[byte] = read_byte(address+byte);
// sprintf(hex_data, "%02x ", line[byte]);
// Serial.print(hex_data);
Serial.print(line[byte], BIN);
Serial.print(" ");
}
// print char
for (int ascii = 0; ascii < stepp; ascii++) {
if (line[ascii] < 32 || line[ascii] > 126) {
Serial.print(".");
} else {
Serial.print((char) line[ascii]);
}
}
Serial.println();
}
}
void setup() {
Serial.begin(115200);
Wire.begin();
//write_byte(254, 105);
//print_ascii_table();
print_char_table();
//print_binary();
/*
int my_data[10] = {};
write_array(1, my_data, 10);
int data[10];
read_to_array(1, data, 10);
for (int i = 0; i < 10; i++)
{
Serial.print(data[i]);
}
*/
}
void loop() {
}
EEPROM memory content:
Tauno Erik 