ESP01 ESP8266 Serial WiFi Transceiver Module 1MB Flash

Description of ESP01 ESP8266 Serial WiFi Transceiver Module 1MB Flash The ESP8266 ESP-01 is a Wi-Fi module that allows a microcontroller to easily connect to a Wi-Fi network. This module is a self-contained SoC (System on a Chip); it can provide internet access to a microcontroller, just like using a Wi-Fi shield with an Arduino, or it can be directly programmed to connect to a Wi-Fi network and also perform microcontroller tasks. On the ESP-01 board, only four GPIO pins are exposed. With built-in TCP/IP support, AT command firmware, onboard LED, and low-power operation, the ESP-01 is ideal for IoT prototyping, home automation, sensor networks, and serial-to-Wi-Fi communication systems. As a result, the ESP8266 is highly versatile and helps reduce both the cost and size of your projects. Do Not Use: This module is not 5V tolerant. Applying a direct 5V input may result in immediate and irreversible damage!!! Technical Specification Parameter Details CPU 32-bit RISC Tensilica Xtensa LX106 @ 80 MHz Instruction RAM 64 KB Program RAM 96 KB Flash Memory 1 MB Wi-Fi Standard IEEE 802.11 b/g/n GPIO 4 pins Operating Voltage 3.3V Typical TX Current 170 mA Typical RX Current 56 mA Deep Sleep Current ~10 µA Dimensions 24.80 × 14.30 mm ESP01 ESP8266 Serial WiFi Transceiver Module Pinouts Pin Name Safe to Use? Notes / Boot Behavior / Warnings 1 GND ✔️ Ground reference. 2 GPIO2 ✔️ Safe Usable as normal GPIO. Must be HIGH during boot. Avoid pull-down sensors. Works with LEDs, digital sensors, I²C pull-ups, etc. 3 GPIO0 ⚠️ Usable with restriction Must be HIGH to boot normally. LOW forces flash mode. Safe if device does not pull LOW during reset. 4 RX (GPIO3) ⚠️ Usable but risky Default UART RX. Receives boot messages. Can cause boot failure if pulled LOW by a sensor. 5 TX (GPIO1) ⚠️ Usable but risky Default UART TX. Sends boot logs. Usable as output after disabling UART. Must not be pulled LOW at boot. 6 CH_PD / EN ❌ Not GPIO Must stay HIGH for ESP to run. Never use as GPIO. 7 RST ❌ Not GPIO Active LOW reset. Keep pulled HIGH. Do not use as GPIO. 8 VCC (3.3V) ✔️ Requires a stable 3.3V supply with 200–250 mA capability. Power Requirement Operating voltage: 3.3V only Peak current during Wi-Fi transmission: up to 200 mA Not 5V tolerant — direct 5V connection will damage the module When using a 5V MCU (Arduino Uno, Mega, etc.): Use a voltage divider on the MCU TX → ESP01 RX line ESP01 TX → MCU RX can be connected directly (3.3V logic is read as HIGH) For stable operation, a dedicated 3.3V power supply is recommended unless using an ESP01 adapter board with onboard regulator and level shifting. How to Program? 1. Using AT Firmware (Default) The module comes with AT commands pre-installed, allowing direct configuration through any serial terminal at 115200 baud (Both NL & CR). Example: AT → Response: OK AT CWMODE=1 → Station (STA) mode AT CWLAP → Scan available Wi-Fi networks 2. Using Custom Firmware To upload custom code (Arduino IDE, ESP8266 SDK, or Lua): For Plug & Play Programming use a ESP01 ESP8266 Serial WiFi Transceiver Programmer Adapter Select “Generic ESP8266 Module” in the Arduino IDE board manager A quick search on Google will yield numerous online tutorials covering these platforms. Some notable examples include: Installing the ESP8266 Board in Arduino IDE Application The ESP01 ESP8266 module is ideal for: IoT automation Smart home devices Wireless sensor networks Wi-Fi-enabled relays and switches Remote data logging Serial-to-Wi-Fi communication Cloud-connected monitoring systems MQTT, HTTP, and TCP/IP applications Packaging Detail 1 × ESP01 ESP8266 Serial WiFi Transceiver Module 1MB Flash Document Datasheet ESP01 ESP8266 Serial WiFi Transceiver Module 1MB Flash Schematic ESP01&ESP01S AT Firmware and Flasher Warranty and Replacement TechShopBD offers up to one year of warranty and replacement support for its products, depending on the supplier(s) and product(s). The specific warranty duration for each product can be found on the respective product page. To be eligible for warranty and replacement support, customers must agree to our terms and conditions. Attention Note: This item is non-returnable. If this item arrives damaged or is not functioning properly, please don’t hesitate to contact us to determine if further action is required. Need Help? Our engineers are available to assist you. If you have any queries, please leave a comment below or call 09678110110 from 09:00 am to 06:00 pm (7 days a week). You can also reach us via WhatsApp or Facebook Inbox