PIC16F887 I2C AT24C16B EEPROM LCD Using XC8

Overview

The AT24C16B is a serial EEPROM with a storage capacity of 16K. It uses I2C interface to communicate with microprocessor. The controller can write data to this memory up to 1 million cycles, with a 100 year data retention. 

 

AT24C16B DIP 8

For more details about this chip you can check its datasheet.

Features

Write Protect (WP) pin must be wired to GND to allow data read and write. The operating voltage is between 1.8V to 5.5V DC. 

Block Diagram

This device is internally organized with 128 pages of 16 bytes each, the 16K requires an 11-bit word address for random word addressing.

Device Address

With page 0 addressing we can use 0xA0 for I2c Write and 0xA1 for I2C Read.

PIC16F887 XC8 Programming

In this example, I use a PIC16F887 micro-controller to write and read data to and from this EEPROM chip. Those ASCII data will show on a 16x4 character LCD.

/*
 * File:   main.c
 * Author: Admin
 *
 * Created on January 5, 2024, 9:50 AM
 */
 
#include <xc.h>
#include "config.h"
#include "i2c.h"
#include "lcd.h"
 
const write_address=0xA0;
const read_address=0xA1;
 
uint16_t write_24c16(uint16_t address,uint8_t *data){
    uint16_t write_size=0;
    i2c_start();
    i2c_write(write_address);
    i2c_write(0);
    while(*data){
        i2c_write(*data++);   
        write_size++;
        while(WCOL);
    }
    i2c_stop();
    return write_size;   
}
 
uint8_t *read_24c16(uint16_t address, uint16_t size){
    uint8_t temp[16];
    for(uint16_t i=0;i<sizeof(temp);i++) temp[i]='\0';
    for(uint8_t i=0;i<size;i++){
        i2c_start();
        i2c_write(write_address);
        i2c_write(i);
        i2c_stop();
 
        i2c_start();
        i2c_write(read_address);  
        temp[i]=i2c_read(0);  
        i2c_stop();
    }
    return temp; 
}
 
void main(void) {
    OSCCONbits.IRCF=7;
    lcdInit();
    i2c_init(1000);
    uint16_t length=0;    
    lcdCommand(0x0C);
    __delay_ms(100);
 
    length=write_24c16(0,"PIC16F887 24C16B");
    __delay_ms(10);
    lcdString(read_24c16(0,length));
 
    lcdXY(1,2);
    length=write_24c16(20,"I2C Programming");
    __delay_ms(10);
    lcdString(read_24c16(20,length));
 
    lcdXY(1,3);
    length=write_24c16(40,"With MPLABX IDE");
    __delay_ms(10);
    lcdString(read_24c16(40,length));
 
    lcdXY(1,4);
    length=write_24c16(60,"XC8 C Compiler");
    __delay_ms(10);
    lcdString(read_24c16(60,length));
 
    while(1);
    return;
}
 

This I2C EEPROM chip requires a read and write time between 5ms and 10ms. On start up, It will need to wait for a little time. I use 100ms delay at start up.

Proteus Simulation

Proteus simulation creates a good result. However using a real hardware we need to fix all related issues.

PIC16F887 DIY PCB

Click here to download its source file.