AT24C32 I2C EEPROM

Name: AT24C32 I2C EEPROM
Brand: Microchip
Availability: InStock

AT24C32

Microchipinterface io display

The AT24C32 is a low-voltage I2C EEPROM with 32K bits of memory, organized as 4096 words of 8-bit each.

Manufacturer datasheet

Buy · DigiKey Buy · Mouser Buy · Amazon

In stock

Specifications

Operating Voltage: 1.8V to 5.5V
Supply Current: 0.4mA (READ at 100 kHz), 2.0mA (WRITE at 100 kHz) mA
Interface: I2C
Resolution: 8-bit
Range: 32K bits (4096 words of 8-bit each)
Accuracy: Not applicable
Temperature Range: -55°C to +125°C (Storage: -65°C to +150°C)
Package: 8-pin PDIP, SOIC, or TSSOP

Pinout

Pin	Name	Functions
1	A0	GPIO
2	A1	GPIO
3	A2	GPIO
4	GND	GND
5	VCC	POWER
6	WP	GPIO
7	SCL	I2C
8	SDA	I2C

Interactive pinout

Highlight:

AT24C32

Click a pin to copy its name · tap a tag above to spotlight a bus.

Starter code

Community starter examples — minimal, unofficial, and provided to get you wiring fast. Verify against the manufacturer datasheet before relying on them.

Arduino (C++)

arduino

// AT24C32 I2C EEPROM (4 KB) — community starter example
// No library needed: 2-byte word address + data.
#include <Wire.h>

const byte EEPROM_ADDR = 0x50;   // A2..A0 = 000

void writeByte(uint16_t addr, byte data) {
  Wire.beginTransmission(EEPROM_ADDR);
  Wire.write(addr >> 8); Wire.write(addr & 0xFF);
  Wire.write(data);
  Wire.endTransmission();
  delay(5);   // write cycle
}

byte readByte(uint16_t addr) {
  Wire.beginTransmission(EEPROM_ADDR);
  Wire.write(addr >> 8); Wire.write(addr & 0xFF);
  Wire.endTransmission();
  Wire.requestFrom(EEPROM_ADDR, (byte)1);
  return Wire.read();
}

void setup() {
  Serial.begin(115200);
  Wire.begin();
  writeByte(0, 42);
  Serial.println(readByte(0));   // -> 42
}

void loop() {}

MicroPython

python

# AT24C32 I2C EEPROM (ESP32) — community starter example
# No driver needed: writeto_mem / readfrom_mem with a 16-bit address
from machine import Pin, I2C
import time

i2c = I2C(0, scl=Pin(22), sda=Pin(21))
ADDR = 0x50

i2c.writeto_mem(ADDR, 0, b"\x2a", addrsize=16)   # write 42 at address 0
time.sleep_ms(5)
print(i2c.readfrom_mem(ADDR, 0, 1, addrsize=16))  # -> b'*'

Wiring

Pin	Arduino Uno R3	ESP32 DevKitC (WROOM-32)	Notes
VCC	+5V	3V3	1.7-5.5 V
GND	GND	GND
SCL	A5/SCL	GPIO22	I2C clock
SDA	A4/SDA	GPIO21	I2C data
A0/A1/A2	-	-	Address select -> 0x50-0x57
WP	GND	GND	Tie LOW to allow writes (HIGH = write-protect)

Typical uses

Non-volatile storage (settings, logs)
RTC modules' companion memory