Arduino Tutorial #9: Leonardo vs. Uno

I received my Arduino Leonardo in the mail today, so I thought I'd go over the difference between it and my Uno. I'm going to using the Leonardo in some future videos to demonstrate dual Arduino capabilities, and what the Leonardo can do.

[snaprollinpitts]

I love the way you just slap those boards around.

[Tronic]

Answered all my questions, thank you.

[humanHardDrive]

You use the extra analog pins like you would the standard ones. On the back of the Leonardo is printed the names of the extra analog pins. The keyboard and mouse features work really well, I've only run into a few bugs with them.

[thatguyontheright]

So they can be used for the same thing, basically. The only real difference is that the Uno needs to have it's USB signals translated to for the AT34, while the Leonardo doesn't.

[StealthB]

Oh I see, so because the 32u4 can interface directly with the USB, the Arduino IDE won't write the bootloader via the RX/TX which you would normally connect to another blank MCU. I'm sure the library will be extended to include this capability for the Leonardo also.

As far as I'm concerned, the UNO still seems the better choice at the moment. The addition of more I/O pins is of course welcomed, but if more pins are needed, you can always connect additional MCUs via the I2C.

Good video btw!

[FutureInventions]

Great video! How can you switch between digital and analog input for the extra analog pins? Also how has the mouse/keyboard feature been working for you?

[humanHardDrive]

It depends. You should technically be able to, but some charging cables only transfer power and not data.

[humanHardDrive]

I'm sure Arduino will continue to produce the Uno. The only reason they couldn't produce a removable chip version of the Leonardo is because the Atmega32u4 used doesn't come in a through-hole package. In regards to the VUSB library, I'm still trying to get one of my own working. It's an extremely useful library but it has quite a bit of overhead. I know that there are some great tutorials out there already.

[kim]

So which one should I buy as a beginner?

[MichaelJeffers]

hHDD, have you made (or will you make) video(s) depicting an Arduino's multipurpose capabilities?  I am wanting to know how many different sketches or libraries an Arduino can run at the same time.  I am learning how to build an automated indoor green house and want to know if I can manage all my sensors, relays and other devices from a single Arduino, or will I need a separate Arduino for each aspect of the grow environment.

[humanHardDrive]

Do you mean program the 32u4 with the Uno, or program another arduino with the Leonardo.

[humanHardDrive]

The Leonardo will actually behave as a USB device, be it a mouse, a keyboard, or whatever you can write the driver for. The Uno only has the ability to behave as a virtual serial port, unless you do some clever coding.

[caffeinatedinsanity]

Leonardo also has more interrupt pins available, no?

[StealthB]

With the UNO it is also very easy to program pretty much any ATmega chip used in Arduinos, with or without an external 16MHz oscillator, just by connecting the RX and TX wires and uploading the bootloader from the Arduino IDE, by using the ATmega328 as intermediary. Can you do that with an ATMega32u4?

[reactorsystem]

The Leonardo is certainly a welcomed update to the main Arduino board, but every article that speaks of Leonardo that I've been reading seems to dodge this obvious "downgrade":
With Uno, it was easy to swap the AVR chips. This is no longer possible with the Leonardo.
Are they going to keep producing the Uno? Btw, do you have some tutorial on the VUSB library?

[BlizzGo]

Would you recommend the Mega R3 or the Leonardo R3.  Cost is a issue but not really a big issue for me.

[StealthB]

My question was if you can program other ATmegas using the Leonardo.

I know you can program other ATmegas using the UNO, including the 168, the 2560 and probably even the 32u4.

[MrBobWareham]

How come your Leonardo has more white paint on the bottom mine that I have just received in its box has only got paint on one
end not all over like yours is mine a forgery?

[ttttkk]

can i use a normal samsung phone charger on Leonardo ?

[humanHardDrive]

Not naturally. The 32u4 bootloader creates a VCOM port that loads the program over USB into RAM, bypassing the serial port. You would have to write software that takes what is in RAM, and translates it to the serial pins.