The ESP-01 ESP8266 Serial Wi-Fi Module is the world’s most famous low-cost solution for adding wireless connectivity to any project. At Electrapac, we recommend this module for makers and engineers in Bangladesh who need to bridge the gap between their microcontrollers and the internet without the bulk of a full development board.

Product Overview

The ESP-01 is a self-contained System-on-Chip (SoC) with an integrated TCP/IP protocol stack. While it is often used as a "Wi-Fi adapter" for an Arduino via AT commands, it is actually a powerful 32-bit microcontroller in its own right. With 1MB of Flash memory (in our latest version), it can host small web servers, send sensor data to the cloud, or act as a smart switch for home automation.

Key Features for Electrapac Customers

• Ultra-Compact Footprint: Measuring just 24.7 X 14.4mm, it is small enough to be embedded into light switches, sensors, or miniature robotics.

• Standalone Operation: You don't need an Arduino. You can program the ESP-01 directly using the Arduino IDE or MicroPython to control its two GPIO pins.

• Integrated Antenna: Features a high-efficiency PCB trace antenna, providing reliable range within a typical home or office environment.

• AT Command Ready: Comes pre-flashed with "AT" firmware, allowing you to connect to Wi-Fi by simply sending text commands over a serial connection.

• Low Power Management: Supports Deep Sleep mode, consuming as little as 10 µA, making it ideal for battery-powered IoT sensors.

Wiring & Programming Guide

Using the Electrapac ESP-01 requires careful attention to its 8-pin layout:

1. VCC & CH_PD: Both must be connected to 3.3V for the module to turn on.

2. GND: Connect to your power supply ground.

3. GPIO0: To enter "Flash Mode" (to upload code), this pin must be connected to GND during power-up. For normal operation, leave it disconnected.

4. TX & RX: Connect to your USB-to-Serial adapter (TX to RX, RX to TX).

CRITICAL WARNING: Never connect the ESP-01 directly to 5V. Using a 5V power supply or 5V logic signals from an Arduino Uno without a level shifter will permanently damage the module. Always use a dedicated 3.3V regulator.

Primary Applications

• Home Automation: Creating Wi-Fi-controlled switches for lights and fans.

• Wireless Data Logging: Sending temperature or humidity data from a DHT11 sensor to a web dashboard.

• Smart Agriculture: Monitoring soil moisture in remote fields and sending alerts to your phone.

• IP-Based Security: Integrating with simple sensors to notify you of door or window activity.

• Wireless Serial Bridge: Sending data between two microcontrollers wirelessly across a room.

Why Shop at Electrapac?

We source our ESP-01 Modules with the upgraded 1MB Flash (Black PCB version) to ensure compatibility with modern firmware and larger Arduino sketches. Visit us at for the IoT components that put the "Smart" in your next smart-home project.