Hardware I2C / SPI capability for breakout & sensor interfacing.Trinket may be small, but do not be fooled by its size! It's a tiny micro-controller board, built around the Atmel ATtiny85, a little chip with a lot of power.The 2 shared IO pins have 2 more analog inputs and one more PWM output. The 3 independent IO pins have 1 analog input and 2 PWM output as well. 5 GPIO - 2 shared with the USB interface.No need to unplug/replug the board every time you want to reset or update!
Reset button for entering the bootloader or restarting the program.On-board green power LED and red pin #1 LED.Power with either USB or external output (such as a battery) - it'll automatically switch over.Up to 16V input, reverse-polarity protection, thermal and current-limit protection. On-board 3.3V or 5.0V power regulator with 150mA output capability and ultra-low dropout.
~5.25K bytes available for use (2.75K taken for the bootloader).We really worked hard on the bootloader process to make it rugged and foolproof, this board wont up and die on you in the middle of a project!.Micro-USB jack for power and/or USB uploading, you can put it in a box or tape it up and use any USB cable for when you want to reprogram.USB bootloader with a nice LED indicator looks just like a USBtinyISP so you can program it with AVRdude (with a simple config modification) and/or the Arduino IDE (with a few simple config modifications).