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331  Using Arduino / Programming Questions / Re: do libraries save space ? on: December 18, 2013, 12:06:41 am
They may or may not save space, but they certainly save time and get your projects up and running faster.

As long as the person who wrote the library knew what he/she was doing ...
332  Using Arduino / Programming Questions / Re: What does the "?" and ":" do in this Code on: December 17, 2013, 11:58:02 pm
Code:
relayState ? Relay_ON : Relay_OFF

if (relayState) then use Relay_ON otherwise use Relay_OFF

Useful shortcut once you get used to using it.
333  Using Arduino / LEDs and Multiplexing / Re: New around with a strange problem(8x8 matrix) on: December 17, 2013, 11:52:44 pm
@CrossRoads, MD_MAX72xx library has the test code for the library functions in sketch referred to by OP.
334  Using Arduino / Audio / Re: LDR with logic pro 9 (midi trigger) on: December 15, 2013, 10:30:33 pm
There is no analogRead() anywhere in the code? That seems like a good place to start looking to me.
335  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: December 15, 2013, 08:49:39 pm
Yes I totally agree! And I have done so 30 times already but it keeps changing back.

http://forum.arduino.cc/index.php?topic=202429.0

The best I can do is a redirect. It is needed anyway because the site has been referenced in a few places outside my control.
336  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: December 15, 2013, 08:10:29 pm
you can define your own character if you want. The current character set does not have your characters.

You need to modify the data file where the font is located (it will have FONT in the name) and replace one of the existing characters with your own. The documentation tells you a bit about the character set definition and if you map out the current data as bits (convert from hex) you should be able to work it out.
337  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: December 15, 2013, 06:45:50 pm
Quote
can you pleas give me the link!

Also in my signature block.
338  Community / Exhibition / Gallery / Re: Scrolling LED matrix display - Parola for Arduino on: December 15, 2013, 02:18:28 pm
Download the latest MD_Max72xx library and read the documentation. There is now a library switch that allows the use of these more common displays. You need to change it before compiling the code.
339  Using Arduino / Sensors / Re: Color Sensor TCS230 on: December 14, 2013, 04:49:42 pm
I think that is a different problem and should be raised in a separate forum discussion panel. There are others who will know far more than I do about that.

I would suggest that you try and experiment with the VirtualWire hardware and library before you use it in your code, as becoming familiar with your tools helps you to use them better.

Good luck!
340  Using Arduino / Audio / Re: MIDI library conflict? on: December 14, 2013, 02:35:31 am
Midifile lib dumps are a formatted version of what is in the SD file, they won't help you as the library by itself works fine. Unless you have turned them on they disappear through the magic of macro substitution.

No idea about the SD card library.
341  Using Arduino / Audio / Re: LDR with logic pro 9 (midi trigger) on: December 14, 2013, 02:33:33 am
Reading the LDR is just reading the analog input and printing the value you get back. It's a standard example that comes with the IDE.

You will get a change just by exposing it to light shading it with your hand/finger.
342  Using Arduino / Audio / Re: MIDI library conflict? on: December 13, 2013, 06:58:01 pm
If you are narrowing it down to SMF.load() then start putting debugging message in the SMF.load() routine and see if that is going on there.

The load() routine is the first time that the SDFat libraries are called to open a file, so there could be interactions there.

Combining libraries is not a good idea, especially as this will require an even greater knowledge of coding that what you need to do what you are doing now.

There is no easy way to debug this other than keep tracing to where the thing dips out, including in the libraries.
343  Using Arduino / LEDs and Multiplexing / Re: limit rows on MAX7219 for matrix display ? on: December 13, 2013, 06:51:10 pm
5x8 would come from the scan limit, 5x7 comes from not wiring one of the bits.

Parola library sits over the top of the 'hardware' library MD_MAX72xx. This library has recently been upgraded to allow use with the more generic hardware available on eBay and other sources (which is basically 'flipped' 90 degrees). One or other modes may suit, depends on the actual details of the wiring. I figure for the cost of a download and a compile of the test program (which exercises the scan limit) it is worth a try. If it does not work no-one is worse off :-)
344  Using Arduino / LEDs and Multiplexing / Re: limit rows on MAX7219 for matrix display ? on: December 13, 2013, 04:22:42 pm
Try using the MD_MAX72XX library (link in the repository below). My Parola modules are probably wired the same way as your matrix and you may find that the scan limit works the way you expect.
345  Using Arduino / Audio / Re: MIDI library conflict? on: December 13, 2013, 04:18:07 pm
The MEGA has more RAM and more program memory as well. It also has a lot more I/O pins.

166 bytes left over is fine if it never changes. It means that you have enough RAM. Remember that you don't needs lots, you just need enough. There are things you can do (like use flash RAM to store strings, making loop counters uint8 instead of int) that will increase the amount of RAM available for other things.

RAM is used by 2 things - one is the program stack and the other the memory heap. The stack usually grows from the bottom up and the heap is allocated from the top down. So if you run out of space, the stack and the heap collide in the middle.

The stack hold all the temporary variables that are being used by a function when it is called and the return address. So, having lots of nested function calls and/or lots of temporary variables makes the stack grow faster.

Most libraries, if they use RAM, will have allocated all they need after the setup() or begin() type routines. Some, however, will allocate memory as required, and this is where the 166 bytes may cause issues. I know that MIDIFile will not allocate additional RAM, and you should look at the MIDI library for malloc(), alloc() or new() function calls, and when they occur.

Unfortunately, when you use someone else's library this stuff is hard to determine and depends on the skill of the library builder (which in many cases is not high, in Arduino land). Remember too that adding debugging messages takes up space and may sometimes be the cause of problems, especially when you are close to full RAM usage.

If you have removed the strings as suggested and you now see more free RAM available, but still see the 'reset' problems, then I am guessing that it is probably not RAM starvation but something else.
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