What's on Board? - Micro-B USB connector for simple connectivity to a PC - Power with either USB or external output(such as a battery)- it will automatically switch over - Headers for an FTDI port for reprogramming - On-board green power LED and red pin #13 LED GPIO pins (18 pins) - 16MHz clock rate, 28K FLASH available - Reset button for entering the bootloader or restarting the program.
The Adafruit Pro Trinket development kit is the bigger, more powerful sister of the Trinket (RS 124-5509, 124-5506) with roughly 4 times the performance and GPIO.
You can also use an FTDI cable to connect to the FTDI port for a serial connection. The Pro Trinket is programmable using the AVRdude and/or the Arduino IDE, and there is a reset button for entering the bootloader or restarting the program as well as LED indication for bootloading. Uses the Atmel ATmega328P microcontroller, 28K of flash, 2K of RAM and 18 GPIO. The pro trinket features Microchip’s ATtiny85 MCU with 8KB program flash, 20 MIPS CPU, 5 PWMs, 2 8 bit timers. Small form factor means it can easily be incorporated into prototype/ design.