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4606  Using Arduino / General Electronics / Re: Vibration effect on the EM devices ? on: September 03, 2011, 10:14:17 am
What is it you are trying to find?

"Any Electromagnetic device" seems to make your search parameters to include anything that uses electricity.  In which case, vibration will affect any components which exhibit piezoelectric characteristics.  Mechanically everything that vibrates will eventually fail.
4607  Using Arduino / Installation & Troubleshooting / Re: RX Pin Not Responding on: September 02, 2011, 08:19:11 pm
Quote
I don't know how to reset the memory in the board, it has a button but it doesn't appear to be doing anything.

"Reset" means "restart."  The Arduino will start running whatever code it is programmed with.
4608  Using Arduino / Programming Questions / Re: Exponential Functions for Fusion Acceleration on: September 02, 2011, 07:07:08 pm
As I've tried to point out before, the math you are using is flawed.  Raising a large number like 5000 by any power is going to result in answers much larger than long can hold...

CycleCount and Answer:
1   5000
2   25000000
3   1.25E+11   // Long can't hold this value.
4   6.25E+14
5   3.125E+18

In any event, why would you want a "flash" that lasts 1,250,000,000,000 seconds?
4609  Using Arduino / Project Guidance / Re: Multidimensional query on: September 02, 2011, 06:29:25 pm

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Is it not typical or even possible with Arduino to have an object oriented firmware ?
I would lean towards not "not typical."  Generally, microcontroller control things which tends to be procedural.  The Arduino language is baed on C++.  To me, it could make sense to have an object as a data structure.  However, I doubt I would ever implement a MVC model.

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I don't know what influence the frequency of 30MHz has over the circuit design
The shift register you are using might be capable of receiving data up to 25MHz (not sure where 30 is coming from), but the Arduino is certainly not capable of transmitting data that fast.

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SN74HC165N's, but I believe 74F151
The 165 is a shift register.  The 151 is a multiplexer.  The shift register will give you the status of all of its Inputs during a single read-out operation.  With a multiplexer you tell it which specific input you are interested in.  I imagine the code and hardware implement is roughly the same.
4610  Using Arduino / Programming Questions / Re: Is this line of code legal? on: September 02, 2011, 06:19:36 pm
Maybe a good question would be, why do you think it may not be "legal"?
4611  Using Arduino / Programming Questions / Re: Serial Monitor - how to open automatically? on: September 02, 2011, 11:06:28 am
I know how you feel about having to reopen the serial monitor.  Over time I found that memorizing the "Upload" and "Serial Monitor" short cuts help.   Habitually I just hit the Serial Monitor's hotkey after the LEDs stop flashing.

Late night troubleshooting is made interesting when I am waiting for serial output from a program that doesn't have any.  smiley-wink
4612  Community / Bar Sport / Re: My Paper Shredder is 1 MIPS on: September 01, 2011, 10:34:05 pm
Quote
So what would lure a mid-level incompetent narcissistic executive close enough to the shredder to snag his neckwear?

A nineteen-year old secretary admin.
4613  Using Arduino / Installation & Troubleshooting / Re: MacBook Air on: September 01, 2011, 10:00:46 pm
Does the problem still occur if unplugging the Mega before going to sleep?

Personally, I unplug all USB (and display) devices before going to sleep.  Their tendency to wake the machine back up on disconnect is annoying.
4614  Using Arduino / Installation & Troubleshooting / Re: MacBook Air on: September 01, 2011, 09:36:34 pm
"re-open it a bit after,"

I looked at my clock and "a bit" doesn't appear.  How long is that?
4615  Using Arduino / Programming Questions / Re: Exponential Functions for Fusion Acceleration on: September 01, 2011, 12:38:19 pm
Code:
unsigned long int myTime=10000;
unsigned long int cycleCount=0;
This complied?  I don't know what an "unsigned long int" is.  I think you meant "unsigned long".


Also, you might find it helpful to put a deliberate "delay(500);" (or something smaller) after the Serial.println().  Some Arduino boards don't like slamming the serial port with data too fast.
4616  Using Arduino / General Electronics / Re: Connecting 5 V to pin? on: August 31, 2011, 07:52:23 pm
Quote
I measured the input resistance of an analog pin with a normal multimeter,

Using a multimeter to measure resistance of an active circuit generally won't yield the results you expect.  You should never use a multimeter to measure resistance if power is applied to a circuit.
4617  Using Arduino / Project Guidance / Re: PHP serial output problem on: August 31, 2011, 05:19:54 pm
What is the default baud rate the php library uses?

As rob suggests, the Arduino is likely resetting when the php script disconnects.  So if the LED turns on, it is probably turned off immediately.  You might have to look at disabling AUTO-RESET to make this script work.
4618  Using Arduino / Project Guidance / Re: If light falls below x LUX, Activate LEDs on: August 31, 2011, 05:13:23 pm
There is a pretty extensive Photocell tutorial link on that same product page.  Probably far more detailed we could give you in a forum post. 

Try working through that tutorial and ask questions based on that work.
4619  General Category / General Discussion / Re: How many? on: August 31, 2011, 04:41:04 pm
Quote
Yes, but how many of them were just in stock somewhere.
Yes, this is why I use the launching of the Uno.  As you might remember, when the Uno was released only a handful of vendors carried it and they were quickly sold out until a 2nd batch came through production. 

Since that time there have been two official revisions of the Uno in addition to the unofficial production runs.  Which is why I said in my original message, that launch gives a order of magnitude for the number.
4620  Using Arduino / Programming Questions / Re: Stack variables = unexpected memory overhead on: August 31, 2011, 12:11:26 pm
So what happens if you put this same code in a loop?

void fn (bool condition)
{
  int x=0;
  for(x=0; x<1000; x++) {
     if (condition)
     {
       char buf[100] = "boo";  // Reserve a 100 character array
       Serial.println (buf); // Just here to stop compiler optimising buf out completely, which it will otherwise
     }
   }
}

Wouldn't the complier have to include code to allocate buf on each iteration of the for() loop?
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