I needed one more Arduino board, so I planned to check out this cheap (US$14.30) Duemilanove 2009 Atmega 328P SCM Board with USB Cable board.
This is a clone of the Arduino Duemilanove with several enhancements not available in the original Arduino. The most important that is on board 2.54 grid male pin headers an power for all PWM and Analog pins. So for most Arduino applications where there is need to connect several sensors and/or servos there is no need to buy a Sensor Shield to connect sensors and servos.
The board constructions feels good and there are clear labels on both sides. It feels really a well designed and well built board.
Operating Voltage: 5 V
Input voltage (nominal): 7~12 V
Input voltage (limits): 6~20 V
Digital I/O pins: 14 (of which 6 provide PWM output)
So this board is is your average Arduino with extra pins for pwm/pwr/gnd for easy use of servos and analog sensors. So no need for Sensor Shield. Here is example where I have connected two RC servos to the servo pins (extra on this board) and then connected a string of LEDs to the original Arduino connectors. The connections work well in both ways.
It must be noted that this board is not the newest Arduino design (UNO) for this kind of board, this board is based on older Duemilanove. In this case I don’t consider the older design any way worse than the newer one, there are even details that I like in older design. The communications is done with FT232RL chip like in original Arduino Duemilanove. I prefer this over the approach used in Arduino UNO, which often needs messing with the driver installation. The serial chips from FTDI are well supported out of the box on modern Windows systems and Linux without any extra trouble.
Whatever your use, this is a decent microcontroller board for a great price.