This is a great kit! I would here suggest an improvement for the bootloader.

Now we need to re-power the MCU to make the switch between bootloader and application effect. I recently played with another ATMEL MCU, and found it is easy to avoid this. The solution is to have some code to jump from bootloader to application and vice versa. After firmware update, a serial command will be issued to jump to application, and when "make" tries to update firmware, it will send a command so MCU can jump to bootloader. The lower level of pin 14 should be kept, in case something is wrong in the application so we can re-power the MCU after pin 14 is connected to ground. And also keep the compatibility.

I know this won't work for the MCUs I ordered, since this also requires update for bootloader, but it will be nice to have it for future MCUs.

Xiangrui