What is the Diffrence Between Arduino MEGA ADK R2 and R3?

I am planning to buy an Arduino MEGA ADK But saw the there are two versions of it available on a few online stores. So would just like to know what is the main difference between Arduino MEGA ADK R2 and R3??

And considering the 7$ - 10$ cheaper price tag of an Arduino ADK Revision 2 (R2) on a few websites, is it actually worth paying more for an R3?

Also has anyone used the ADK and has it been more useful and productive? Or do you suggest buying a MEGA 2560 R3 instead....

Thankx in Advance for the Advice :)

This page:

http://arduino.cc/en/Main/ArduinoBoardADK

Says the difference is:

Revision 2 of the MegaADK board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU mode.

Revision 3 of the board has the following new features: 1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible both with the board that use the AVR, which operate with 5V and with the Arduino Due that operate with 3.3V. The second one is a not connected pin, that is reserved for future purposes. Stronger RESET circuit.

My opinion is the R3 board would-be worth the extra $. At a minimum the pin changes will make it more compatible with future shields, and the reset fix is worthwhile otherwise once in a while you have to reboot the board by hand, and it gets annoying.

As far as the ADK board vs the Mega 2560...I'm an iPhone guy so I can't speak about it directly, but I can tell you I've been playing with Arduino for about 18 months now and so far haven't really heard anything about the ADK one way or the other, beyond the press releases.

Hope this helps.

mehtaatur: Also has anyone used the ADK and has it been more useful and productive? Or do you suggest buying a MEGA 2560 R3 instead...

The MegaADK is just a Mega2560 with a built-in USB Host chip. If you plan on using your Arduino as a USB Host (to an Android device or any other USB device) then it will be more useful.

@Chris Thankx.

And also ive read a few posts on the net saying that the Mega boards are not very useful and have few issues with compatibility, so what would you suggest??

mehtaatur:
Just wanted to ask that if I buy a Mega 2560 instead of a ADK will I still be able to wireless connect it to cellphones, like without using shields (I mean via internet and USB connection).

Haven’t you already asked this?

And also ive read a few posts on the net saying that the Mega boards are not very useful and have few issues with compatibility, so what would you suggest??

That is a difficult question to answer without knowing what you want to do. Do you just want to experiment and tinker, or do you want to build something specific?

mehtaatur: @Chris Thankx.

And also ive read a few posts on the net saying that the Mega boards are not very useful and have few issues with compatibility, so what would you suggest??

  1. The Mega boards are as useful as any other arduino (or clone) board. Usefullness is driven by the user's application needs.
  2. All arduino boards past and present have some differences that may or may not be an issue with a specific application.

Lefty

@ Lefty, Thankx

@ Chirs, talking about specific application, I am planning to try complete home Automation. Wanna Try controlling all the home Electronics (like switches, AC's, TV, etc. also Monitor Power Usage). This Kind of Application Would require lots of I/O so ive chosen the ADK for it.

:)

Sounds cool, and something I want to get into some time.

My opinion, if i was doing it: I don't want the ADK board because it talks to Android via a USB. I want something that uses WiFi (or Bluetooth), I don't want to have to walk to a specific place in my house and plug in a cable every time I want to make an adjustment.

I also don't think I'd want to run everything from a single Mega (or Uno etc.) controlling everything directly, that would just be too many power cables running everywhere. I'd have one controller managing a bunch of satellite devices over WiFi or phone line, x10, etc.

I probably would go with the Mega version, however, just for the additional memory space.

This is just how I think I will do it one day; I'm definitely not trying to criticize your project.

Good luck!

Thankx for the Advice and Suggestions.

Two things I would wanna ask:

1) As you mentioned above about use of WiFi or Bluetooth, what Hardware or shields would you recommend for this purpose.

2) Since there is gonna be a requirement to an External Power Supply to control the Bigger Appliances, I am thinking of using relays to establish the switching connection (ON, OFF). Do you have any suggestions for using any component other than relays?

Any Tips/Suggestions regarding this would be Appreciated.

Thankx :)

Don't be a help vampire http://slash7.com/2006/12/22/vampires/! Do your own research, post your thoughts and then let people make suggestions.

AndrewStone: Don't be a help vampire http://slash7.com/2006/12/22/vampires/! Do your own research, post your thoughts and then let people make suggestions.

Help vampires, so that's what you call them. ;)

@ mehtaatur - The things I know that can control high amperage devices are mechanical relays, solid state relays, and triacs. I've never worked with SSRs or triacs but relays are easy to do with an Arduino; there's at least one example here on arduino.cc.

The thing about relays is, they scare me. Actually they don't scare me as much as the thought of making just one small mistake or miswiring or something I overlooked or didn't know about in design, and having my house burn down. I'd probably trust myself with a relay controlling something like a sprinkler system or lamp that's only on when I'm in front of it, but if I was going to use it to control an unattended heater or ceiling light I'd probably get something like:

https://www.adafruit.com/products/268

or

http://www.x10.com/automation/sr227_s.html

so I'd have someone to sue if things go wrong...

Regarding wireless -- I've worked with, and like, the Async Labs WiShield for WiFi, but they stopped selling it last March. SparkFun sells one that some people like and some people complain about; I've never used it so I can't comment. The "official" Arduino WiFi shield was announced last fall but hasn't actually started shipping yet; if you look around the forum you'll see plenty of people (myself included) are anxiously awaiting it's release.

@ AndrewStone - Thanks for the laugh.

Thankx M8.

Will post an Update once I make some nice progress on the Project :)

This comment may not be just right (actually, probably not right at all) for this thread, but I thought that I would go ahead and register with the Arduino forum, and throw in my two cents (however worthless it might be) anyway. I am new to the Arduino, and while trying to figure out how to control two prop motors thru the R3 Motor Shield with a Mega 2560 R3, I found a forum (now closed) where someone (with very good and useful information and details, for which I am grateful) suggested that having this combination would wreck the ability to communicate with the arduino using additional shields such as an ethernet, wifi, or others that require use of the sp1 system, due to the common use of pins 11, 12 & 13 for sp1. This concerned me as I also have a R3 Ethernet Shield that I was hoping to use. Well after a bit of poking around I came to the conclusion that this is true for the smaller (& older) boards, but the Mega boards use pins 50, 51 & 52 for SP1, leaving pins 11, 12 & 13 available for whatever ( such as control inputs that may be needed for a specified purpose with another shield that you find that you want to use). If I had bought a smaller version Arduino I would have been in a bind already. Though, I believe that with some creativity one faced with that type of compatibility issue may be able to cut the 11, 12 & 13 pins jumpers to the top shield (in this case motor shield), and jumper to these locations from some other available logic pins, and change the pin numbers in the code accordingly, but things are already confusing enough (at least for me)as they are. I think that I got lucky, as I only had a rough idea what I wanted to do, I picked the Mega 2560 over the smaller boards (just in case) and Radio Shack only had the R3 versions on the shelf. Of coarse I still do not know much about what I am doing. I see a lot of people scratching their heads on forums looking for a trace of comprehensive guidance that only seems to appear here and there in bits and pieces. Then, in contrast, I see videos of incredible things that other people have built. So I will just continue to plod thru the Arduino wilderness hoping to find myself in a community forum that is in the middle of a gold rush where I can stake a claim and mine for that ever elusive step by step comprehensive guidance that even someone as ignorant as me can understand and implement.