# Adafruit Trinket 5V

> Tiny 31×15mm Arduino-compatible microcontroller with ATtiny85 at 8–16 MHz, 5V logic, 8KB flash, 3 GPIO pins, and Micro USB — the 5V variant for interfacing with 5V sensors and NeoPixel LEDs.

## Quick Facts

- **Brand:** Adafruit
- **Board Type:** dev-board
- **Price:** ~$6.95
- **Product Readiness:** developer
- **CPU:** ATtiny85 @ 8-16 MHz
- **CPU Architecture:** AVR
- **CPU Cores:** 1
- **RAM:** 512 bytes
- **Flash:** 8 KB
- **Power:** 5V via Micro USB or up to 16V external
- **Operating Voltage:** 5V
- **Dimensions:** 31 × 15.5 mm
- **Weight:** 1.85g

## Open Source

- **Firmware:** Yes
- **Schematics:** Yes
- **PCB Layout:** Yes

## Compatible Firmware

arduino

## Use Cases

- maker
- wearable
- led-projects
- neopixel
- embedded-development

## Components

- **ATtiny85** (mcu): 8-bit AVR microcontroller configurable at 8-16 MHz with 8KB flash, 512B SRAM, 512B EEPROM and 5 I/O pins — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2FATtiny25-45-85-Datasheet-DS40002187A.pdf&ref=openhardware.directory&product=adafruit-trinket-5v&source=md-export)

## Protocols

- **I2C**: SDA: D0, SCL: D2
- **SPI**
- **USB**

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| D0 | I2C SDA (ATtiny85 PB0), PWM, Analog Input | I2C | digital-input, digital-output, pwm, analog-input |
| D1 | Digital I/O (ATtiny85 PB1), PWM, Onboard LED (#1 red) | — | digital-input, digital-output, pwm |
| D2 | I2C SCL (ATtiny85 PB2), Analog Input | I2C | digital-input, digital-output, analog-input |
| D3 | USB Data- bit-bang (ATtiny85 PB3), Analog Input | — | digital-input, digital-output, analog-input |
| D4 | USB Data+ bit-bang (ATtiny85 PB4), Analog Input | — | digital-input, digital-output, analog-input |

## Available Software

- **[Arduino IDE]()** (open-source)

## Description

## Overview

The Adafruit Trinket 5V is a miniature Arduino-compatible microcontroller board built around the Atmel ATtiny85, operating at 5V logic to interface directly with 5V peripherals, NeoPixel LED strips, and legacy sensors without level shifting. It measures 31 × 15.5 mm and weighs just 1.85 grams, making it one of Adafruit's smallest and lowest-cost programmable boards.

The ATtiny85 provides 8KB of flash, 512 bytes of SRAM, and 512 bytes of EEPROM. The clock speed is software-configurable: the bootloader starts at 8 MHz and users can switch to 16 MHz in code. Five I/O pins total are available — two shared with USB, leaving three independent GPIOs each supporting PWM, analog input, and digital I/O.

An onboard 5V regulator delivers up to 150mA from input voltages up to 16V, with reverse-polarity, thermal, and current-limit protection. The board switches automatically between USB and external power. The Micro USB jack activates the USB bootloader when connected, and a reset button provides manual bootloader access.

The 5V version is particularly popular for driving NeoPixel LEDs and other 5V logic peripherals where the 3.3V Trinket variant would require level shifting. Adafruit recommends the Trinket M0 for new designs due to the bit-bang USB technique's compatibility limitations with modern computers.

## Where to Buy

- [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F1501&ref=openhardware.directory&product=adafruit-trinket-5v&source=md-export) — 6.95

## Resources

- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F1501&ref=openhardware.directory&product=adafruit-trinket-5v&source=md-export)
- [wiki](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fintroducing-trinket&ref=openhardware.directory&product=adafruit-trinket-5v&source=md-export)

## Tags

`attiny85`, `tiny`, `5v`, `arduino-compatible`, `neopixel`, `adafruit`, `trinket`

## Images

![Adafruit Trinket 5V](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-trinket-5v/121fa72e63f6.jpg)
![Adafruit Trinket 5V](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-trinket-5v/2b56f6e7162b.jpg)

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