Trinket Pro 3V

Trinket has onboard USB bootloading support. There is also added Optiboot support, so you can either program your Pro Trinket over USB or with a FTDI cable just like the Pro Mini and friends.

The Pro Trinket PCB measures only 1.5” x 0.7” x 0.2” (without headers) but packs the same capability as an Arduino UNO. So it’s great once you’ve finished up a prototype on an official Arduino UNO and want to make the project smaller.

The Pro Trinket 3V uses the Atmega328P chip, which is the same core chip in the Arduino UNO/Duemilanove/Mini/etc. However, it uses 3V logic and 12MHz clock which means it’s good when you want a lower-power and lower-voltage setup. Pro Trinket is programmable using the Arduino IDE as you already set up, and 95% of Arduino projects will work out of the box!

Here’s some handy specifications:

• ATmega328P onboard chip in QFN package running at 3.3V logic
• 12MHz clock rate, 28K FLASH available
• USB bootloader with a nice LED indicator looks just like a USBtinyISP so you can program it with AVRdude and/or the Arduino IDE (with a few simple config modifications).
• Also has headers for an FTDI port for reprogramming
• 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.
• On-board 3.3V power regulator with 150mA output capability and ultra-low dropout. Up to 16V input, reverse-polarity protection, thermal and current-limit protection.
• Power with either USB or external output (such as a battery) - it’ll automatically switch over
• On-board green power LED and red pin #13 LED
• Reset button for entering the bootloader or restarting the program.
• Works with 99% of existing Arduino sketches (anything that doesn’t use more than 28K, and doesn’t require pins #2 and #7)
• Mounting holes

Adafruit product website: ID:2010