Wi-Fi
ESP-01 ESP8266 AT Wi-Fi Module
3.3 V ESP8266 module used as an AT-command Wi-Fi adapter over UART.
Generic module using Espressif ESP8266EX
Overview
The ESP-01 is a small ESP8266 module. In BananaBoard's verified Arduino Nano path it runs supported ESP-AT firmware and WiFiEspAT at 57600 baud. Its supply and I/O are 3.3 V only. A 5 V AVR TX signal therefore needs level conditioning before ESP RX, and the module needs a regulated supply sized for Wi-Fi current bursts.
Wiring tip: 3.3 V power and logic only; Nano TX needs a divider before ESP RX; Nano RX can read ESP TX directly
Pins & wiring
Logical two-sided map — confirm the package or board drawing before wiring.
All pins
Hover · click to selectSelected pin
GND
- Direction
- Passive
Full pin table
| Pin | Name | Role | Direction | Voltage | Note |
|---|---|---|---|---|---|
| 1 | Ground | Passive | — | — | |
| 2 | GPIO | Out | — | — | |
| 3 | GPIO | Bidirectional | — | — | |
| 4 | Control | In | — | Must be HIGH for normal operation. | |
| 5 | Control | Bidirectional | — | Keep HIGH for normal boot; pull LOW only while flashing ESP firmware. | |
| 6 | Control | In | — | — | |
| 7 | GPIO | In | — | — | |
| 8 | Power | Power | 3.3 V | — |
Wiring examples
Arduino Nano through WiFiEspAT
arduino-nano pinout →Cross UART directions, condition Nano TX down to 3.3 V, and use a separate regulated 3.3 V supply with common ground.
| ESP-01 ESP8266 AT Wi-Fi Module pin | Connects to | Note |
|---|---|---|
| TX | D8 | ESP TX to Nano SoftwareSerial RX is safe at 3.3 V HIGH. |
| RX | D9 | Through the required 1k/2k divider below. |
| GND | GND | — |
You also need
- Required1 kΩ resistor between D9 and RX_NODE — Series leg of the Nano TX to ESP RX divider.
- Required2 kΩ resistor between RX_NODE and GND — Ground leg that sets the conditioned HIGH near 3.3 V.
- Required470 µF capacitor between VCC and GND — Local bulk storage for Wi-Fi current bursts.
- Do not power the ESP-01 from the Nano's low-current 3V3 pin. Use a regulated 3.3 V supply rated for at least 300 mA and join grounds.
Specifications
Footprint
No independently verified physical footprint is on file for this part yet.
Alternatives
No alternatives are on file yet for this part.
Documents
Datasheets
- ESP8266EX Datasheet Version 7.0Espressif Systems
Frequently asked questions
What voltage does the ESP-01 ESP8266 AT Wi-Fi Module run at?
The ESP-01 ESP8266 AT Wi-Fi Module runs at 3–3.6V, per the spec sheet below. Always double-check against the specific board you have — some breakouts add an onboard regulator that changes the usable input range.
How many pins does the ESP-01 ESP8266 AT Wi-Fi Module have?
The ESP-01 ESP8266 AT Wi-Fi Module has 8 pins, communicating over Digital, UART. See the full pinout table in Pins & wiring for each pin's role.
Can I simulate the ESP-01 ESP8266 AT Wi-Fi Module before ordering hardware?
Not yet — the ESP-01 ESP8266 AT Wi-Fi Module does not have a live simulation model in Banana Board today, so validate the wiring here and test on real hardware.
Where is the ESP-01 ESP8266 AT Wi-Fi Module datasheet?
Linked in the Documents section on this page, and cited on every spec that came from it.
Related references
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