Arduino’s latest incarnation – the Leonardo is now shipping. It is the first Arduino to use Atmel’s ATmegaXU4 series chip with built-in USB. This change is big and it has big benefits.
Early Arduinos required a serial port connection to your computer for programming. As the platform matured, the board acquired a USB to serial conversion chip. The latest version of the classic Arduino board – the Uno – still uses this method, although with the Uno a switch was made from an expensive FTDI conversion chip to using an ATmegaXU2 series microcontroller chip. This chip is a cousin to the U4 series, but lacks analog input pins.
Using a USB conversion chip was only a slight improvement over using a serial connection. It removed the requirement for a special conversion cable, but added significant cost to each and every board. With the Uno, the switch to using the ATmeag8U2 lowered the cost by a few dollars, but it seems kind of silly to use an entire microcontroller just to perform USB to serial conversion for another microcontroller of roughly the same capability.
This ironic situation is finally resolved with the introduction of the Leonardo. Not only does this … Read the rest