Step by Step Guide to the Arduino Leonardo

The Arduino team is now shipping their latest creation - the Leonardo. 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. In addition to the built-in USB, it offers more digital and analog pins. This step by step  guide gives you the details you need to know to start using it.

For a more comprehensive guide, see my article - Arduino Leonardo versus Uno – What’s New.

Step 1: More Digital Pins

There are four more digital pins. The Uno has 14 digital pins: D0-D13. The Leonardo has 18: D0-D17. The extra pins have been mapped to the ICSP header. Their mappings are:

• D14 – MISO – PB3
• D15 – SCK – PB1
• D16 – MOSI – PB2
• D17 – SS – PB0

Pin D17 (SS) does not have a corresponding pin on the ICSP header, nor anywhere on the board. In order to use it, you must solder a wire to either the end of the Rx LED or the via attached to it - see photo.

Comments

[jibblesmgee]

But... you can't remove the microcontroller? I thought the whole point of Arduino was to program a microcontroller, remove it, and then put it in another project... They expect people to buy/make a new board for every project?

I won't be buying one, not unless they start putting a socket on it instead of surface mount soldering it to the board.

[bhubbard45]

All I ever really wanted was an extra 5V pin

[Zaphod Beetlebrox]

IF only I'd know a little earlier I wouldn't have bought an Uno, Thanks for sharing.

[emdarcher]

i know, i bought an uno the day before Maker Faire Bay Area and then it was released there and was introduced by Massimo Banzi himself in his presentation and i felt kinda sad because it was cheaper and better. Luckily i was able to get one before all of the first 100 leonardo's were bought for $20 in the MakerShed there. But then when i got home i examined it and had no idea about the extras, so this instructable has helped me.