Adafruit Feather 32u4 Basic Proto

Feather-format ATmega32u4 board (8 MHz, 3.3V) with a small proto area, native USB, 100mA LiPo charger, and 20 GPIO pins with hardware I2C/SPI/UART. Choose this over the Adalogger when you need prototyping pads instead of microSD.

Logical pinout · physical placement not verified

3V
Type · Power
GND
Type · Ground
BAT
Type · Power
USB
Type · USB
EN
Type · Control
RST
Type · Control
#0RX
Type · UART, Signal
#1TX
Type · UART, Signal
#2SDA
Type · I2C, Signal
#3SCL
Type · I2C, Signal
#5
Type · Signal
#6
Type · Signal
#9
Type · Signal
#10
Type · Signal
#11
Type · Signal
#12
Type · Signal
#13
Type · Signal
A0
Type · Analog
A1
Type · Analog
A2
Type · Analog
A3
Type · Analog
A4
Type · Analog
A5
Type · Analog
SCK
Type · SPI
MOSI
Type · SPI
MISO
Type · SPI
ARef
Type · Analog

Pin	Type
3V	Power
GND	Ground
BAT	Power
USB	USB
EN	Control
RST	Control
#0RX	UART, Signal
#1TX	UART, Signal
#2SDA	I2C, Signal
#3SCL	I2C, Signal
#5	Signal
#6	Signal
#9	Signal
#10	Signal
#11	Signal
#12	Signal
#13	Signal
A0	Analog
A1	Analog
A2	Analog
A3	Analog
A4	Analog
A5	Analog
SCK	SPI
MOSI	SPI
MISO	SPI
ARef	Analog

Logical pinout · physical placement not verified

Pin details

27 connections

3V
Power
GND
Ground
BAT
Power
USB
USB
EN
Control
RST
Control
#0RX
UART, Signal
#1TX
UART, Signal
#2SDA
I2C, Signal
#3SCL
I2C, Signal
#5
Signal
#6
Signal
#9
Signal
#10
Signal
#11
Signal
#12
Signal
#13
Signal
A0
Analog
A1
Analog
A2
Analog
A3
Analog
A4
Analog
A5
Analog
SCK
SPI
MOSI
SPI
MISO
SPI
ARef
Analog

Start wiring

USB · 3.3 V

Confirm the data interface matches your host board.

Module pins: 3V, BAT, USB, ARef, GND, #0/RX, #1/TX, #2/SDA. Schematik maps them to your board in the app.

Other MCUs

228 other options

Specialists: Teensy for high-clock audio and USB, Adafruit SAMD boards running CircuitPython or the Arduino IDE, proper STM32 eval kits, and the micro:bit classroom ecosystem. Schematik builds target ESP32, Arduino Uno, and Pico; come here when you have a specific reason to.

View all 228

Related groups

4 groups

Arduino

About 75 boards across every Arduino generation: 5V Uno/Mega/GIGA, 3.3V MKR and Portenta, plus DFRduino and Bluno compatibles. Confirm the voltage rail before stacking any shield.

Boards · Arduino boards · 77 parts

ESP32

Wi-Fi and Bluetooth on a single chip, in every shape from Espressif DevKitC to Adafruit Feathers with STEMMA QT, DFRobot FireBeetles tuned for battery life, and Seeed XIAOs under a thumbnail.

Boards · ESP32 boards · 159 parts

Add-ons

About 270 add-ons across Pi HATs, Arduino shields, and FeatherWings. The same function — motor control, PoE, display — usually ships once per host connector family. Get the host board right first.

Boards · HATs, Shields & add-ons · 270 parts

Pi Pico

The Raspberry Pi MCU line — Pico, Pico 2, and third-party boards on the same silicon — plus a deep bench of Pico-pinout displays, loggers, and radio modules that do nothing without a Pico plugged in.

Boards · Pico & RP2040 boards · 43 parts

Pinout