Deprecation Warning: The Trinket bit-bang USB technique it uses doesn’t work well on many modern computers. We no longer recommend it; consider the Trinket M0 for better capabilities and built-in USB.

The Adafruit Trinket is a tiny yet powerful microcontroller board based on the Atmel ATtiny85. Designed to be small and low-cost, it fits into any project without sacrificing functionality. It is ideal when you want a compact and affordable Arduino-IDE programmable board.

The ATtiny85 features 8K of flash memory, 5 I/O pins including analog inputs, and PWM outputs. The USB bootloader allows programming over USB like an Arduino, making the Trinket a mini Arduino board for simple projects.

Key Features:

• ATtiny85 microcontroller with 8K flash, 512 bytes SRAM, 512 bytes EEPROM
• Internal oscillator at 8 MHz, configurable to 16 MHz via software
• USB bootloader with LED indicator for easy programming
• Micro-USB connector for power and programming
• On-board 3.3V or 5.0V regulator with 150mA output
• Automatic power switching between USB and external power
• Reset button to enter bootloader or restart
• 5 GPIO pins (2 shared with USB), including analog inputs and PWM outputs
• Hardware I2C and SPI support for sensor interfacing
• Compact size with mounting holes

This is the 5V version of the Trinket, capable of running at 8 MHz or 16 MHz. The 3V version is also available for 3V logic applications.

Limitations:

• No serial port support – no serial debugging capability
• USB v3 ports on some computers may not recognize the bootloader; use USB v2 or a USB hub instead

The board dimensions are 1.2″ x 0.6″ x 0.2″ (31mm x 15.5mm x 5mm) and weight is approximately 1.85 grams (without headers).

For more detailed information including pinouts, tutorials, and programming examples, see the Introducing Trinket tutorial.