Adafruit Pro Trinket - 3V 12MHz
Here's some things you may have to consider when adapting Arduino sketches:
- Pins #2 and #7 are not available (they are exclusively for USB)
- The Pro Trinket 3V runs at 12MHz, this doesn't affect most projects. Only the most timing-specific libraries may be affected, check the documentation! The NeoPixel Library works fine at 12MHz.
- The onboard power supply is a 3.3V regulator and it can provide 150mA output
- You cannot plug shields directly into the Pro Trinket
- There is no Serial-to-USB chip onboard. This is to keep the Pro Trinket small and inexpensive, you can use any FTDI cable to connect to the FTDI port for a Serial connection. The USB connection is for uploading new code only.
- The bootloader on the Pro Trinket use 4KB of FLASH so the maximum sketch size is 28,672 bytes. The bootloader does not affect RAM usage.
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! Yeah!
Once headers are installed they can be fitted into 0.6" wide sockets