I have to figure out which of my USB ports is the actual COM3 (I have 5 USP ports) how do I find out which one is COM3 pointed at?

That's not how it works. Things plugged into USB ports become COM ports; USB ports themselves, are not COM ports.

How do I know I have a good COM port cause it seems if it knows my device is there

Unplug the Arduino. Check the Tools > Serial Port menu and take note of anything currently listed. Plug it in, and check the menu again. The new one would be the correct one.

and as far as the problem with my laptop how do I get it to recognize that its even hooked up?

Try re-installing the drivers.

Could be a bad driver.
Could be the wrong COM port selected.
Could be something hooked up to the Arduino that is messing with its ability to communicate.

Here is a good website building sensor networks with the nrfs: http://maniacbug.wordpress.com/2011/11/02/getting-started-rf24/

The JeeNode is a pretty popular (and cheap device) for building small RF networks with the RFM12B module: http://jeelabs.com/products/jeenode

I have a small sensor network setup that use the RFM12Bs (which are more expensive than the nrf's, but a smaller form factor) ATTiny84 chips, and custom PCBs. The result is a node that costs less than $10, so if you want to go really cheap, it's certainly possible.

The first option seems sensible and wouldn't be too difficult to code; you just have to give each individual node its own address and when you send the data, send a "To" address as well.

the errors.

What errors?

Post ALL of your code.

So will RF modules be able to achieve these tasks do you believe?

There are other concerns that affect the feasability of wireless solutions such as distance, reliability, noise, and power that you haven't outlined. That makes it difficult to answer your question. RFM12B and nRF24L01 are two of the more popular and widely supported transceivers to use with Arduino. There are also cheap on-way communication modules that can be used as well.

How would do a Function for this?

Start by addressing the concerns laid out in my previous response.

Well, first you have to identify which of the variables you are trying to change, and which you are just need the value from. That will affect how the variable is passed, be it by value or by reference.

If you were to take the lines as you posted them, yyyyyyy and fffffff would need to be passed by reference because you are changing the values. However, based on the examples you gave, I get the feeling you should be using digitalWrite() and analogWrite() with yyyyyyy and fffffff instead, which would make it a pass by value scenario. I would start with a very simple sketch to get a function working before your try to incorporate it into your main sketch. This will give you a better environment to learn how the code works.

Also, what AWOL said about commas.

I just want to lcd.print the word LED1

Then surround LED with quotes. If it is not surrounded by quotes, the compiler will look for a variable with that name.

So I need to do this to all the text I want to print?

No, that was just an example. Like this:

Code:

char line1[] = "hamster";
lcd.print(line1);

Code:

lcd.print("hamster");

These two blocks of code will produce the same result on the lcd.

Do i need to do a char somewhere for all of them?

Either that, or you use constant strings:

Code:

menuLedOn ("something", "something else", "Led1", 1);

Here's another simple example:

Code:

void sentence(char *animal, char *action, int times)
{
  Serial.print("The ");
  Serial.print(animal);
  Serial.print(" ");
  Serial.print(action);
  Serial.print(" ");
  Serial.print(times);
  Serial.print(" time(s)");
}

Given this block of code, you could print out different sentences using different arguments:

Code:

sentence("dog", "licks", 8); // The dog licks 8 time(s)
sentence("cat", "purrs", 1); // The cat purrs 1 time(s)

So did I get it right:

Nope. When you surround text in quotes before passing it to something like lcd.print, you're telling the compiler that you want the text in between the quotes to be printed:

Code:

char line1[] = "hamster"
lcd.print("line1"); // will print "line1" to lcd
lcd.print(line1); // will print "hamster" to lcd

So when you make a call like this:

Code:

menuLedOn (ON, OFF, LED1, LedPin1S)

LED1 must be a declared variable somewhere.

Sorry, about that, let me rephrase that.

When you said "very minimal Arduino", what did you have in mind for :

- A sensor that detect door activity? Got a link to it?

A simple magnetic sensor such as those you see on most doors/windows for security systems.

- An Arduino model/shield combination to react on the sensor detection?

Haven't used a WiFi shield, so I couldn't recommend one, but as far as a minimal Arduino:

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

...and how will the signal get from the Arduino to the computer? Or can it send a notice via SMTP (email) to a smartphone directly?

https://www.google.com/search?q=arduino+send+email

Code:

     bpm = x / (duration / 60000);

Since duration is going to be less than 60000, the result of that division will always be 0 (integer division). It seems like there is a much simpler way to do this: On a positive (or negative, doesn't matter) transition record the time. On the next transition, find the time difference (you're calling it duration). That gives you the milliseconds/beat. Dive 60000 by that number and you have the beats/minute.

My first though would be to keep track of the transition times for each device. If you detect a transition time below a certain threshold, turn everything off. Doesn't sound like anything too complicated.

Depends on what your current code looks like.

I'm trying to print on a 2x16 lcd:

ON             >
OFF             

And when you scroll down the next thing to print would be:

OFF            >
ON

So constant strings should be surrounded by quotes. Variables shouldn't. Here's is a quick example:

Code:

// function declaration
void debugPrint(char *label, char *value)
{
  Serial.print(labal);
  Serial.print(" = [");
  Serial.print(value);
  Serial.println("]");
}

// later in the code when you want to call it:
char someValue[] = "True";
debugPrint("The Value in someValue", someValue);

In the Serial monitor, we would see:

Code:

The Value in someValue = [True]

Take not of when double quotes are appropriate.