When testing an Arduino board, I encountered some strange problems. I decided to build such a board from scratch to find out what the problem was. I had some ATmegaxx8 target boards from Evil Mad Scientists (see [1]) available, so I decided to convert one of them into an Arduino compatible board for testing.
ATMEGA168P on the Evil Mad Scientists Board
The design of the target board is inspired by the Arduino Pro from Sparkfun. It does not have an on-board regulator, but is otherwise compatible. The serial port is brought out to a 6-pin header with is compatible with Sparkfuns FTDI Basic Breakout (3.3V or 5V). A ZIFF-socket is provided for easy replacement of the processor – and thus the board can be used to program bootloaders into empty devices …
Schematics
The board uses an 8MHz resonator, so there are no speed problems when powering the board with 3.3V or 5V. The Arduino bootloader is “ATmegaBOOT_168_pro_8MHz.hex” from the Arduino distribution. The proper fuses are:
low fuses = 0xc6
high fuses = 0xdd
ext. fuses = 0x00
Programming of the boot loader was done using AVR Studio 6 with an AVRISP mkII programmer.
[1] http://www.evilmadscientist.com/2008/tiny-portable-avr-projects-business-card-breakout-boards/