The New Arduino UNO Revision 3 has just arrived in the Maker Shed! This is a refresh of the wildly popular Arduino UNO that has been updated to allow for for additional functionality and future shield flexibility. Here are the main differences:
- The USB controller chip has been upgraded from an ATmega8u (8k of flash memory) to an ATmega16u (16k of flash memory.) This new chip should make it easier to emulate input devices like joysticks, mice, MIDI interfaces, and keyboards (this has not yet been tested and there is no code yet.)
- Analog pins 4 and 5 have been broken out next to the AREF pin to allow for I2C communication. This makes it easier for future shields to be compatible with both UNO’s and MEGA’s. Also, the power pin has been duplicated next to the RESET pin to let shields know what voltage they are running (in the case of the UNO it’s 5 volts.)
- The reset button has moved next to the USB input for easier accessibility while a shield is in place.
There are a couple other subtle changes (like the FCC certification logo on the back) but the main things, like the processor, number of pins, driver, board size, upload speed, etc, have not changed. The Arduino Revision 3 is compatible with all current shields and code.