I have thought about minimizing the Arduino board because what I found in many cases was that I didn't need the FTDI USB interface once the sketch was loaded, and I thought the Arduino board is kind of 'big' for its contents.
So here is a summary of my concept of mini Arduino compatible board. Its name will be 'JeonLab mini.'
* 28-pin DIP ATmega328P with Arduino bootloader
* Digital pins from 2 to 13 are arranged on one side
* Analog pins from 0 to 5 are arranged on the other side along with the FTDI-USB connector for an external FTDI breakout board
* There is no reset switch, but header pins for RESET and GND are provided
* A power LED and #13 LED
* A 0.1uF capacitor for the auto-reset when uploading a sketch
* Headers for power inlet (+5V and GND)
* Small enough to fit in a small plastic box


Any comment will be appreciated.
Jeonlab