The ESP-01S is an upgraded version of the original ESP-01 module, built around the ESP8266EX chip from Espressif. It's a compact, low-cost WiFi module that adds wireless networking to any microcontroller project with minimal extra hardware.
Unlike the original ESP-01, the ESP-01S includes an improved onboard power management circuit, giving it more stable operation particularly useful when connecting via USB-to-serial adapters that can't always supply clean, sufficient current. It also adds a blue status LED on GPIO2 for quick visual feedback during flashing or operation.
The module ships pre-programmed with AT command firmware, so it can be connected straight to an Arduino (or any 3.3V-tolerant microcontroller) via UART and controlled with simple serial commands no additional firmware flashing required for basic use. For more advanced projects, it's also fully compatible with the Arduino IDE and NodeMCU/Lua firmware for custom programming.
Key Specifications:
- Chip: ESP8266EX (Tensilica L106 32-bit low-power MCU)
- WiFi: 802.11 b/g/n, 2.4GHz
- Flash memory: 1MB
- Operating voltage: 3.3V (do not connect to 5V)
- I/O voltage tolerance: 3.6V max
- Serial interface: UART (default baud rate 115200 bps; some firmware versions use 9600)
- Onboard status LED (GPIO2)
- Pin count: 8-pin (VCC, GND, TX, RX, CH_PD/EN, RST, GPIO0, GPIO2)
Typical uses:
- Adding WiFi connectivity to Arduino or other microcontroller projects
- IoT sensor nodes and remote monitoring
- Basic home automation and smart switches
- Low-cost prototyping before moving to a full ESP32/ESP8266 dev board
Note: The ESP-01S operates at 3.3V logic and is not 5V tolerant a logic level shifter or direct 3.3V microcontroller connection is required when interfacing with 5V boards like a standard Arduino Uno. A separate USB-to-serial programmer (e.g. an ESP-01/ESP-01S USB adapter) is recommended for flashing custom firmware. We also stock a breadboard adapter for use in your projects.
What's in the box?
1 x ESP8266 ESP-01S WiFi Serial Transceiver Module
Respurces
Instructables.com offer some help on this board as well as on medium.com
Note: Stock is currently available in South Africa for national shipping!
