WiFi Module ESP8266-ESP01
📡 ESP8266-ESP01 WiFi Module – Serial TTL
Add WiFi to Your Arduino or Microcontroller Projects
The ESP8266-ESP01 is a compact and low-cost WiFi module based on the powerful ESP8266 SoC, designed to provide wireless connectivity to microcontrollers like Arduino, STM32, and AVR via serial communication (UART/TTL). It supports full TCP/IP protocol stack and can operate as a client, server, or even a standalone microcontroller.
⚙️ Technical Specifications
| Parameter | Specification |
|---|---|
| Chipset | ESP8266EX |
| Operating Voltage | 3.3V DC (⚠️ do not use 5V directly!) |
| Current (avg) | ~80 mA (peak up to 200 mA) |
| Interface | UART (TX/RX TTL serial) |
| WiFi Standard | 802.11 b/g/n |
| Modes | STA / AP / STA+AP |
| Antenna | PCB trace antenna |
| Flash Memory | 1MB (varies by version) |
| Dimensions | 25mm x 15mm approx. |
| IO Pins | GPIO0, GPIO2 (multipurpose use) |
✅ Features
📶 Adds WiFi connectivity to any microcontroller with UART
⚙️ Supports AT commands and firmware upgrades
🧠 Can act as a standalone microcontroller (with custom firmware)
💾 Compatible with Arduino IDE when flashed with NodeMCU or AT firmware
🔁 Reliable for IoT, home automation, and smart devices
🔌 Pinout
| Pin | Function |
|---|---|
| VCC | 3.3V (required) |
| GND | Ground |
| TX | Serial Transmit |
| RX | Serial Receive |
| CH_PD | Enable (connect to 3.3V) |
| RST | Reset (optional) |
| GPIO0 | IO / Flash mode |
| GPIO2 | IO |
🧪 Example Application: Connect to Arduino Uno
Use a 3.3V regulator and level shifter (or voltage divider) for RX:
CopyEditArduino TX ➝ ESP01 RX (via voltage divider to 3.3V) Arduino RX ⬅ ESP01 TX (direct) 3.3V ➝ VCC, CH_PD GND ➝ GND