[the USB controller in UNO and Mega2560 does not work well]

My advice: get a AVR programmer and avoid the USB connection for uploading sketches.

Yes, I insist: the USB controller in UNO and Mega2560 does not work well

[Yes, it's a standalone laptop and I'm logged in as Admin.]

Massimo,

* Are you logged in as an administrator? some companies give employees laptops with less "powerful" logins and that  proved to be an issue when adding new devices.
Yes, it's a standalone laptop and I'm logged in as Admin.

* are you running some antivirus/filewall type thing (yes some people have them on mac too..)
Nope. It's almost a factory default (plus OpenOffice, Firefox and Arduino's SDK)

* Check any other driver that might interfere with serial ports or network devices.
Factory defaults. Nothing else installed. The only additional hardware is a plain Mac mouse.

* Do you have drivers installed for USB 3G/GSM modems? a number of 3G/GSM modems show up with the same kind of usb device as the Arduino UNO. One of those drivers might interfere (I have one installed and it has all sorts of amusing bugs)
Nope. Never plugged anything else to this Macbook Pro apart from USB hard drives, mice and Arduino.

And again, similar problems happened with different computers in my company. And this week we detected problems also flashing it from Linux, problems that become more frequent when the sketch grows. It was impossible to flash any Uno board with a 29KB sketch.

In my opinion, it's obvious that something is going wrong with the Uno/Atmega2560 boards; just have a look in the troubleshooting section and you will see... Nothing like this happened with Duemilanove.
 

[not use Mac]

Some more info about my case:

• Running MacOSX 10.6.7 on a MacBook Pro 2.53GHz Intel Core 2 Duo 4GB DDR3
• The same thing happened in another MacBook Pro from my team (another owner)
• Problems detected with many different Arduino Uno boards, including Arduino Mega 2560
• The boards were purchased separately, in 3 different batches (approx 2 months between)
• There's no USB Hub in between
• We tried many different USB lines (very short ones, shielded, even different colors  )

Since the same Arduino boards were flashed without any problem from a Linux station, and never got a single error when unplugging the USB line, I still recommend to not use Mac for this tasks.

After spending many hours with it, I want to share my conclusions just in case it might be helpful for others. If you have a Mac computer and you are planning to work with Arduino Uno (or with the new Mega), my advice is to get another computer with either Linux or Windows, or you will need strong drugs...

The driver for the USB Atmel chipset provided with these boards is not suitable for Mac environments. It seems to have some unpredictable behaviour that usually ends up with Apple's "death screen" when disconnecting the board, or with multiple sync errors when uploading sketches (this gets worst when the sketch is bigger than 25KB).

I hope this can save some time to other developers (at least until another version of this driver is published!).

I've been trying to contact anyone who can solve a mistake in the distributors webpages (both Spanish and English versions) without success. Do I have any other way to file a complain about that?

Both pages are not in sync at all, many distributors are missing, others repeated and, in our case, the link is wrong. (Yes, I'm a reseller)

Can somebody help me with this?

Thanks.

Os informo que Domino (el software para domótica sobre Arduino creado por el equipo de OpenDomo.org) soporta desde la recién estrenada versión 0.4.0 el acceso mediante web:

http://es.opendomo.org/domino-040

La Ethernet Shield va como una seda, y ofrece acceso no solo mediante web, sino que también permite acceder desde Telnet. La configuración, como es habitual, se hace mediante comandos, y no requiere "flashear" Arduino a cada cambio.

Espero que os sirva!

Salud

Desde hace algún tiempo iniciamos un sub-proyecto de OpenDomo (http://opendomo.org) basado en domótica sobre Arduino, al que bautizamos como Domino. Este sub-proyecto consiste en un firmware para Arduino que convierte la placa en una plataforma de automatismos, fácilmente programable y con una gran variedad de funciones, tal como podéis ver en la página oficial del proyecto: http://es.opendomo.org/domino

Uno de los próximos pasos a seguir es adaptar este firmware para dar soporte al Ethernet Shield de Arduino, pero al no disponer del dispositivo no lo hemos podido llevar a cabo aún. Si en este foro hay algún usuario interesado en usar Arduino como elemento de control domótico en red, tal vez quiera echar un vistazo a las posibilidades de Domino, ya que podría serle de utilidad.

Por ahora, la utilidad del puerto Ethernet está planteada como conexión por socket, emulando el actual puerto USB, pero tal vez podamos estudiar la posibilidad de incorporar algun soporte básico para HTTP más adelante, en cuanto podamos verificar su funcionamiento.

Estoy intentando desarrollar funcionalidades para el bus RS-485 y no encuentro buenos ejemplos sobre Arduino. ¿Alguno de vosotros tiene experiencia en este campo? ¿tenéis conocimiento de algún proyecto funcional similar?

Gracias de antemano!