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1  Forum 2005-2010 (read only) / Syntax & Programs / Re: Java and clock speed on: March 08, 2010, 05:43:04 pm
Buffer the data from the serial input, then split the buffer at the linefeed and process the data before the LF, then wait for the buffer to fill with data for the next LF (hex 0x13 iirc)

"SerialPortEvent.DATA_AVAILABLE" doesn't mean it has got all the data you want, only that "some data" is available. The serial code at

http://www.arduino.cc/playground/Interfacing/Java

does not know that you want to process a data packet terminated with linefeed. you have to code that yourself.
2  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: bug: unsigned long works as int on: April 28, 2010, 02:54:33 pm
May, or may not be related, but you declare:
Code:
int ledArray[14]=
{
  1,1,1,1,1,1,1,1,1,1,1,1,1,1};

but you iterate from an illegal position here:
Code:
void ledjes() {
   for (int i=15;i>-1;i--) {
      int waarde=ledArray[i];
   }
...
3  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Is this a bug or am I missing something? on: April 03, 2010, 03:38:55 pm
See:

http://c-faq.com/expr/preservingrules.html

In short "To avoid surprises (under either set of rules, or due to an unexpected change of rules), it's best to avoid mixing signed and unsigned types in the same expression"

PS: Edit: g++ with -Wall args warns about this. I would like to have such warnings present in Arduino Uno Punto Zero
4  Forum 2005-2010 (read only) / Interfacing / Re: need help  LED matrix on: December 04, 2009, 05:33:31 pm
Hi,

8x8 led matrix = 64 points. even the arduino mega has "only" 54 digital I/O's so you cant use that board without some external logic IC's, sorry...

5  Forum 2005-2010 (read only) / Interfacing / Re: sleepy arduino, wake up call. on: December 04, 2009, 06:11:06 pm
Mike, thank you very much for the tip on the hardware Timer1, I was not aware about that, and it might be what I need!
6  Forum 2005-2010 (read only) / Interfacing / Re: sleepy arduino, wake up call. on: December 04, 2009, 06:01:26 pm
DS1305 then? "Two programmable time-of-day alarms are provided by the DS1305. Each alarm can generate an interrupt on a programmable combination of seconds, minutes, hours, and day."

This could probably save my day. I dont need such accurancy, actually. I could need more diversion on the trigger. Given a set of lot of devices, they should not trigger on the same time, but I can program my way out of that. I would have hoped for a simpler sollution, but this is a good direction to examine! thanx for the suggestions so far!

7  Forum 2005-2010 (read only) / Interfacing / sleepy arduino, wake up call. on: December 04, 2009, 04:57:41 pm
Hello all, arduino newbie here.

I'm working on a project where power requirements is a big issue, and looking into saving power by entering sleep mode.

I'll probably use the arduino pro mini 3.3v for maximum power savings.

The problem is the wake up call, getting the arduino into sleep is no problem, but I need to wake up the aurdino about 2 times in 24 hours to do some work via an interrupt. And I cannot depend on daylight source.

Timing of the wakeup is not so important, only in a 24 hour timeline it should have triggered about 2 times. I'm thinking about a resistor/capacitor/transistor trigger on the interrupt line, but I'm not sure what values to use to minimize idle power usage for the wake up circuit on a 12 hour cycle, and avoiding usage of big electrolytes.  Any ideas or pointers to help me with this?

btw, a Big Thank You, to the people and community making the arduino hw/sw. This is fun stuff!!

kind regards from Norway.
8  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: GUI on: March 06, 2010, 02:27:06 pm
A clicky'drag'drop GUI will probably help developing basic tasks, but you'll almost always be dropping into the cryptic magic texts to fine tune and do what you really want.

I've been programming for several decades, so I probably have a skewed point of view of this, but I find satisfaction of really understanding how things work at the low level, to use that knowledge to exploit every bit of performance of the hardware.

The arduino is not your heavy duty minicomputer that has shitloads of resources available, so it is vital to understand the limitations, and instead try to learn how to best utilize this to your needs.

Unfortunately, click'n'drag'n'draw type GUI's will mostly generate code that quickly eat your available resources.

Whats very good about arduino, is that its open source, you dont need to invest a shitload of money to get a development kit, there is a large community that is using it, and there is already a ton of resources on how to do things with it. And, if you get past a certain point in the learning curve, you could do amazing things with very cheap hardware.

Remember, amazing things could be done with the commodore 64, and that was a 1mhz cpu with 64KB ram :-)

That said, there is nothing wrong to develop a click'n'drag GUI for the arduino, and it probably would broaden the user base, but there is lego mindstorms out there already, and having a bit more hard core, cheap, open source alternative is a great portal of doing amazing things with a microcontroller. I'll say that investing time to learn the magic text of programming C/C++ will be very rewarding in the long run.

I live by "Find, and use the right tool for the job", and "if its fun and rewarding, keep doing it", arduino is a very nice tool for many things, and it is extremely fun to work with, Your results may vary.

9  Forum 2005-2010 (read only) / Bar Sport / Re: Sparkfun overpriced on: July 10, 2010, 06:05:33 pm
Quote
When you buy something from Sparkfun do not even think about returning it.
If the product is defective they will attempt to fight you tooth and nail.
Their customer product support rating is -10 on a scale of 0 to 10. (10 being the highest)
That may be your experience, but not mine. I've received a shipment from them without a vital, very expensive item ($50), replaced by a very cheep item($0.1), but a simple email, with photographs of received items, was fixed very swiftly, quick and kindly from sparkfun, no extra questions asked, no fuzz, even if I live half a world apart. I'll give a +10 for customer support from them. Prices compared to my neighborly countries, sparkfun is quite reasonable, and their website is quite active and exciting.
10  Forum 2005-2010 (read only) / Uno Punto Zero / compiler warnings (-Wall) on: April 03, 2010, 06:45:34 pm
In Arduino Uno Punto Zero, I would like to see better handling of compiler warnings, (-Wall) (more precise line error/warning handling).

And, I would like to give a big thank you to all making this possible (ide, hardware designers, gcc, atmel, etc. for creating arduino possible ) keep up the good work, I've have a lot of fun and inspiring work with this stuff THANX!



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