# Adafruit HUZZAH ESP8266 Breakout

> Breadboard-friendly ESP8266 WiFi breakout at 80 MHz with 802.11 b/g/n, 9 GPIO, 3.3V logic, 500mA regulator, and pre-loaded NodeMCU firmware — Adafruit's accessible entry point to ESP8266 development.

## Quick Facts

- **Brand:** Adafruit
- **Board Type:** dev-board
- **Price:** ~$9.95
- **Product Readiness:** developer
- **CPU:** ESP8266 Tensilica L106 @ 80 MHz
- **CPU Architecture:** Xtensa LX106
- **CPU Cores:** 1
- **RAM:** 80 KB
- **Flash:** 4MB
- **Power:** 3.3V via external supply or USB-serial 3.3V-6V input
- **Operating Voltage:** 3.3V
- **Dimensions:** approximately 23 × 18 mm
- **Antenna:** Built-in PCB antenna

## Connectivity

- **Wifi:** 802.11 b/g/n

## Open Source

- **Firmware:** No
- **Schematics:** Yes
- **PCB Layout:** Yes

## Compatible Firmware

arduino, micropython, Tasmota, esphome, platformio

## Use Cases

- iot
- wifi-projects
- home-automation
- maker
- prototyping

## Components

- **ESP8266** (soc): Espressif ESP8266 Tensilica L106 at 80 MHz with full 802.11 b/g/n WiFi, integrated TCP/IP stack, 80KB RAM — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2F0a-esp8266ex_datasheet_en.pdf&ref=openhardware.directory&product=adafruit-huzzah-esp8266&source=md-export)

## Protocols

- **UART**: TX: GPIO2, RX: GPIO3
- **SPI**: MOSI: GPIO13, MISO: GPIO12, SCK: GPIO14, SS: GPIO15
- **I2C**: SDA: GPIO4, SCL: GPIO5
- **WiFi 802.11 b/g/n**

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| GPIO0 | Digital I/O, Boot mode select (LOW=flash, HIGH=normal), Onboard red LED | — | digital-input, digital-output |
| GPIO2 | Digital I/O, UART TX (Serial1) | UART | digital-input, digital-output |
| GPIO4 | I2C SDA (software) | I2C | digital-input, digital-output |
| GPIO5 | I2C SCL (software) | I2C | digital-input, digital-output |
| GPIO12 | SPI MISO | SPI | digital-input, digital-output |
| GPIO13 | SPI MOSI | SPI | digital-input, digital-output |
| GPIO14 | SPI SCK | SPI | digital-input, digital-output |
| GPIO15 | SPI SS (pull low at boot) | SPI | digital-input, digital-output |
| GPIO16 | Digital I/O, Wake from deep sleep | — | digital-input, digital-output |
| ADC | Analog Input, 0–1.0V maximum | — | analog-input |

## Available Software

- **[Arduino IDE]()** (open-source)
- **[NodeMCU]()** (open-source)
- **[MicroPython]()** (open-source)
- **[ESP-IDF]()** (open-source)

## Description

## Overview

The Adafruit HUZZAH ESP8266 Breakout is a compact, breadboard-friendly development platform built around the Espressif ESP8266 WiFi microcontroller. Running at 80 MHz with a full 802.11 b/g/n WiFi stack (supporting both client and access point modes) and an integrated TCP/IP stack with DNS, it enables internet-connected embedded projects at a very low cost.

The breakout includes an onboard 3.3V regulator capable of 500mA output, accepting input from 3V to 6V batteries or USB power via two diode-protected power inputs. Level shifting on the UART and reset pins simplifies interfacing with 5V USB-serial adapters. The board comes pre-loaded with the NodeMCU Lua interpreter (v0.9.5), enabling immediate scripting without a separate development environment.

Nine GPIO pins are available (3.3V logic), along with one analog input limited to 1.0V maximum. Hardware I2C and SPI are supported through the GPIO pins. A red LED on GPIO0 and a reset button and user button (for bootload mode) are included for development convenience.

Programming support covers Arduino IDE (via the ESP8266 Arduino core), Lua scripting, and MicroPython. The board requires a separate FTDI cable or USB-to-serial adapter for programming since no USB port is included — a design choice that keeps the board minimal and flexible for battery-powered applications.

## Where to Buy

- [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F2471&ref=openhardware.directory&product=adafruit-huzzah-esp8266&source=md-export) — 9.95

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F2471&ref=openhardware.directory&product=adafruit-huzzah-esp8266&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fadafruit-huzzah-esp8266-breakout&ref=openhardware.directory&product=adafruit-huzzah-esp8266&source=md-export)

## Tags

`esp8266`, `wifi`, `iot`, `breakout`, `nodemcu`, `adafruit`, `huzzah`

## Images

![Adafruit HUZZAH ESP8266 Breakout](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-huzzah-esp8266/72dff193fb2c.jpg)
![Adafruit HUZZAH ESP8266 Breakout](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-huzzah-esp8266/9fe6740a781e.jpg)

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