Adafruit Pro Trinket - 5V 16MHz

Deprecation Warning: The Pro Trinket bit-bang USB technique it uses doesn't work as well as it did in 2014, many modern computers won't work well. It is still available for maintaining older projects but not recommended for new designs. Alternatives include Metro Mini, ItsyBitsy 32u4, and ItsyBitsy M0 boards with native USB and more pins.

The Adafruit Pro Trinket 5V combines the popular Trinket with an Arduino-compatible ATmega328 microcontroller running at 16MHz. The board is compact, measuring only 1.5" x 0.7" x 0.2" (without headers), yet offers 18 GPIO pins, two extra analog inputs, 28K of flash, and 2K of RAM.

Features include USB bootloading via a MicroUSB jack, onboard 5V regulator providing 150mA output, reverse-polarity and thermal protection, reset button, and built-in LEDs for power and pin 13.

The Pro Trinket is compatible with the Arduino IDE and works with 99% of Arduino sketches.

• ATmega328P microcontroller (QFN package) running at 16 MHz
• 28 KB Flash memory (with 4 KB reserved for bootloader)
• 2 KB RAM
• Onboard MicroUSB jack for power and programming
• USB bootloader using Optiboot with LED indicator
• Headers for FTDI serial port for reprogramming
• Onboard 5V regulator with 150 mA output
• Reverse polarity and thermal protection
• 18 GPIO pins and 2 extra analog inputs
• Reset button and power/pin 13 LEDs
• Mounting holes included

Note: Pins #2 and #7 are reserved for USB and not available. Cannot plug shields directly into Pro Trinket. Maximum sketch size is 28,672 bytes due to bootloader.

For more information and getting started guides, visit the Pro Trinket tutorial.