So you really want an ICSP header (D11,12,13, +5, Gnd, Reset) and an USB/Serial adapter header (Rx, Tx, DTR, +5, Gnd, and typically a 2nd Gnd; FTDI chip needs it to pull its CTS (clear to send) input pin low.

Bob, is the FTDI header 5 pins or 6?

That's a cool board!

You know, if you don't need the boot loader you can simply program the AVR processor using the 6 pin ICSP header. Unless you need to field upgrade the device, you don't need the boot loader.

I also have an N2K project I need to work on, but the expense of the protocol and certification is holding me up. Have you had any luck so far?

Or I can build the boards for you.

You could do a lot worse than to have Crossroads do this for you! If the quantity is high, you can buy the CPUs programmed from Digikey. This adds a small cost to each CPU, but they come all programmed and you won't need a human to hook up a programmer and upload the app.

Perhaps a shield that has stacking headers, a LED on each pin and a simple jumper or perhaps DIP switches to disconnect the LED from the pin it is on. That would be pretty easy and cheap to build. However, a better approach is a logic analyzer. It would cost more than a shield, but a logic analyzer is vastly more useful.

How do you do that? Find that distance apart at which you can communicate -- but with difficulty. Shorten the antennas slightly -- test for improvement -- if you see improvement shorten some more.

If it gets worse -- you need longer antennas -- start over. Sorry about that -- try 18cm -- then shorten as per above instructions.

No this is not quite right. The antenna needs to resonate. The 17cm length is approximately 1/4 of the wave length of the frequency in use. The antenna should be cut for the frequency being used. If a 1/4 wave whip is not sufficient, then you can add a ground plane. The ground plane would be a few wires at right angles to the whip and 20% longer. Someone mentioned a dipole. That's two legs, each 1/4 wave long, one fed from the center fo the feed line and the other connected to the braid. These are directional, with signal radiated off their sides.

If this is not adequate, you can build more complex directional antennas.

This is a useful thread. Can I just ask is the router-ip the same as IPv4 address, which is found in cmd->ipconfig?

There are a few different systems but generally no. The cable modem gets a real IP address from the cable system. It then hands out "fake net" addresses to the computers and other devices using a protocol called DHCP (dynamic host control protocol). So the cable modem / FiOS router / whatever might have an IP address like 72.249.12.17 and the computers on your network would have an IP address like 192.168.1.5, 192.168.1.6 and so on.

Is it true to say that the computers IP, (got by Googling 'what is my ip') is different from IPv4 which is the routers IP?

Well, yes and no.

First, IPv4 is a system of IP addresses, which has 4 octets (so xxx.xxx.xxx.xxx). IPv4 is not a reference to the IP on our cable modem.

Yes the computer has its own IP, but the cable modem / router / whatever device translates packets from your PC that go to the Internet so they look like they come from the real IP address. It keeps track, so packets that are supposed to go to your PC get sent to your PC and so on. This is called NAT (Network Address Translation).

As a result of NAT, everything that comes from any PC or device on your network looks like it comes from the one IP address on the cable modem.

Port forwarding is a mechanism where by you tell the cable modem that if a packet comes to your real IP address for port 8080, it should be forwarded to fake IP address 192.168.1.5 (or whatever). That way, an Arduino web server can answer requests.
 

Look through the protocol document I linked to, then use a telnet client to open a connection to your ISPs email server. Just type the commands to learn how it works.

A smart leak, very interesting!

Okay so you have a few options.

First, let me suggest that you check this out:

https://cosm.com/?pachube_redirect=true

This is a free site that you can use to track when the leak is happening so you can see trends.

For immediate alerts, email works. A few words about email. If you have access to an email server, this is easy. If you have a cable modem service, or FiOS or some other type of full time internet service then you have access to an email server. So what you do is connect to the server on port 25, send some simple text commands, then send the text of your email and off it goes! If you're not sending attachments then you can whip this up quickly.

The text commands collectively are referred to as the SMTP Protocol. SMTP == Simple Mail Transfer Protocol, details here:

http://www.smtp2go.com/articles/smtp-protocol.html

Start with the tutorial as Mike said, then check out this protocol and you'll be in business.

Well the main thing is that I want it to be via Wifi, so I will be not using the ethernet shield.

The thing I didnt understood is the part of put the server into the arduino, and storing the web content in the SD Card.

Thank you! you have no idea how much you've help!

Okay on the wifi, do you plan to connect it to an existing wifi router, or does your device need to be the access point itself? If the former, you have several choices for wifi shield to use. If the later, you need a wifi shield that can be configured as an access point. Currently the Roving Networks stuff sort of does this not too well. The Hydrogen wifi shield using the GainSpan wifi chip should do it well, but you need to make sure that the GainSpan module has the latest firmware. There are other shields based on GainSpan, like Juniper, but I have been unable to get vendors to confirm what firmware those wifi modules are running. If it is old, you can't upgrade it unless you spend about $250 on some stuff from GainSpan. So choose carefully.

There is a lot of merit to starting this with an ordinary Ethernet shield then adding wifi later. As the prior poster said, some of what you want to do is in the enet shield examples.  And, the Hydrogen card (which is currently out of stock with its manufacturer) comes with a library that is compatible with the enet library.

Whether it is wifi or wired enet, a web server in its simplest form is a program that receives requests from a client and sends data out in response. Usually, the data sent is files. You web server will want to take files, add some data to them (like are the lights on or off right now) and then send them to the client. These files are the "web content" and need to be stored somewhere. Two choices, the flash memory of the processor or on an SD card. I suppose there are yet other choices, but in practice, these are the two easiest ways to do it. If you do it on the SD card, well then you can update the web content without upgrading the program in the processor. If you don't want to have an SD card, then you have to use the flash. There is not much of it, so you'll be cramped.

Another option is to add SPI flash, but lets not go there yet.

Does that help make things a bit more clear?

 

I agree with Grumpy, except I would probably do it with an ISR. Attach all your limit switches to digital IO lines that are all on the same processor port. An interrupt will be triggered when any line on the entire port changes. Your ISR then goes and checks to see which switch triggered the interrupt.

But either way, it will work and like Mike said, its pretty easy to do.

I am into a project and need a complete email program for the Uno. 

From reading the rest of your post, I wonder if you really need a "complete" email program? Let me suggest that you post the requirements about what the email program needs to do, and what hardware is available for it to run on. Then people could suggest ways to make it work. Off the bat, I can say that compiling the email addresses into the program may not be the best approach, although I can speculate on reasons to do that.

But if you tell us what you're actually trying to do, you'll probably get some help.

The legal stuff does not seem all that bad really. If the original poster wants one just for his own use I don't see any problem at all. As for the hardware and software, I don't see a problem there either. From a technical standpoint I don't see it as a major undertaking. If what we're talking about is a box that just opens in a particular location, and it does not need to be super reliable, well this is not a problem. Maybe the hardest thing to solve is long term battery life. Now if this were a life saving device or a military device, that would be different. But as a hobby thing, any GPS module and a little computer is easy to do.

What I do see as more challenging, at least for me, is the actual box part. I suppose if one were a cabinet maker or a person skilled in word working, that would be the easy part.

So it makes an interesting team, a guy who can make a beautiful box with a little hidden compartment to hide the electronics, and a guy who can do the hardware and software.

 

Well the webserver part is key, so you may want to try to undertand that aspect of the project. What about the web server didn't you understand?

Also, I don't know how current this is but you can check out:

http://code.google.com/p/webduino/