Qwiic EEPROM Hookup Guide

Contributors: santaimpersonator, MAKIN-STUFF
Favorited Favorite 2

Hardware Overview

Board Dimensions

The Qwiic EEPROM Breakout is laid out on the standardized 1" x 1" (2.54 x 2.54 cm) Qwiic breakout board and includes the standard four 0.13" mounting holes, which are compatible with 4-40 screws.

board dimensions
Board dimensions. (Click to enlarge)


There is a power status LED to help make sure that your Qwiic EEPROM is getting power. You can power the board either through the polarized Qwiic connector system or the breakout pins (3.3V and GND) provided. The Qwiic system is meant to run on 3.3V, be sure that you are NOT using another voltage when using the Qwiic system.

Power LED and power breakout pins. (Click to enlarge)


The CAT24C512 IC is a 512-Kb (kilobit) EEPROM flash memory is organized as 65,536 words of 8 bits each with a 128-byte page write buffer. An on board ECC (Error Correction Code) makes this EEPROM suitable for high reliability applications. The IC also offers write protection, which inhibits write operations by pulling the WP pin High (protects the entire memory). The external address pins make it possible to connect up to eight CAT24C512 EEPROM chips on the same I2C bus.

EEPROM chip. (Click to enlarge)

For more details on how the serial EEPROM works, check out our guide below:

Reading and Writing Serial EEPROMs

August 11, 2017

EEPROM is a great way to add extra memory to your microcontroller project. Wait 'til you see how easy it is to use!

Sensor Characteristics

Below, is a table of the characteristics of the EEPROM chip. For more details, please refer to the datasheet.

Characteristic Description
Power Supply Voltage: 1.8 to 5.5V
Supply Current:
  • Read Current: 1mA
  • Write Current: 1.8mA - 2.5mA
Reliability Endurance: 1,000,000 Program/Erase Cycles
Data Retention: 100 Years
Page Write Buffer 128 bytes
Write Protection Entire Memory
I2C Address (7-bit) 1010[E2][E1][E0]
0x50 (Default), 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57

Qwiic and I2C

I2C Address

The Qwiic EEPROM’s I2C address, 0x50 (7-bit), is factory set. An alternate I2C address can be configured to 1010[E2][E1][E0] by modifying the address jumpers E0, E1, E2 (see Jumpers section below).

Qwiic Connectors

The simplest way to use the Qwiic EEPROM is through the Qwiic connect system. The connectors are polarized for the I2C connection and power. (*They are tied to the corresponding power and I2C breakout pins.)

Qwiic connectors
Qwiic connectors. (Click to enlarge)

Breakout Pins

The board also provides five labeled breakout pins.

Breakout pins
Breakout pins. (Click to enlarge)


You can connect these lines to the I2C bus of your microcontroller and power pins (3.3V and GND), for a more permanent connection.

I2C Pins
I2C Connections- The pins are tied to the Qwiic connectors.

Write Protection Pin

Pulling the WP pin high, will disable all write operations to the entire memory space.

Interrupt pins
Interrupt breakout pins. (Click to enlarge)


There are five jumpers on the board. Not sure how to cut or modify a jumper? Read here!

Power LED Jumper

Cutting the LED jumper will remove the 1kΩ resistors and PWR LED from the 3.3V power. This is useful for low power applications.

power LED jumper
Power LED jumper. (Click to enlarge)

Write Protection

Bridging the WP jumper will pull the pin high (to the 3.3V power) and disable any write operations.

WP jumper
Write protection jumper. (Click to enlarge)

I2C Pull-Up

Cutting the I2C jumper will remove the 2.2kΩ pull-up resistors from the I2C bus. If you have many devices on your I2C bus you may want to remove these jumpers.

I2C pullup jumper
I2C pull-up resistor jumper. (Click to enlarge)

Address Jumpers

Modifying the address jumpers (E0, E1, E2) allows users to configure the I2C address. This can be used to configure the default I2C address of the device to 1010[E2][E1][E0] (7-bit).

address jumpers
Address jumpers. (Click to enlarge)