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1  Using Arduino / LEDs and Multiplexing / Re: Potentiometer controlled RGB fade without using serial on: September 18, 2011, 05:56:47 am
I've done something similar when designing a character creator for a game - a slider that selects hue.  I split the bar up into red->red+green, red+green->green, green->green+blue, green+blue->blue, blue->red+blue, red+blue->red and made each section linear interpolate.  Worked quite nicely.
2  Using Arduino / Audio / Re: Reason for using an interrupt? on: September 17, 2011, 03:28:40 pm
I have done that, it's pretty much necessary to get an intelligible sound full stop.  Using the ADC asynchronously allows me to make use of the delay.
3  Using Arduino / Audio / Re: Volume Control using arduino on: September 17, 2011, 11:10:50 am
At a quick glance, you're using = instead of == in one of your if statements.

Also, go learn what a loop is.
4  Using Arduino / Audio / Re: Volume Control using arduino on: September 17, 2011, 03:33:26 am
You could use one of the Arduino's PWM outputs, filter it using a low pass and then using a MOSFET draining to ground (with a resistor before it in the path) vary the volume.  I don't know much of the implementation details not having used transistors much but it feels like the simplest way.
5  Using Arduino / Audio / Re: Reason for using an interrupt? on: September 16, 2011, 07:12:06 pm
Ok, thanks.  It seems to work either way.  I was wondering why only that one example did that, maybe the author misunderstood.
6  Using Arduino / Audio / Re: Reason for using an interrupt? on: September 16, 2011, 03:51:25 pm
Ooh, one more thing along the same lines - I looked at some examples, and one incremented, then decremented, incremented and decremented again an unused variable between changing the ADMUX and starting the conversion, with the comment "short delay before start conversion".  Is this necessary?  I can't find any evidence that it is.
7  Using Arduino / Audio / Re: Reason for using an interrupt? on: September 16, 2011, 01:23:49 pm
Ah, ok, thanks.  I don't really need anything like that so I'll keep it simpler, thanks.
8  Using Arduino / Audio / Reason for using an interrupt? on: September 16, 2011, 11:40:21 am
I'm experimenting with using a 328-based Nano 3.0 as an audio processor, and have written a pretty good chorus/flanger but want to experiment with more CPU intensive stuff.  As I do more in my loop, it takes longer to complete and the sample rate drops below the threshold I'm currently sitting on below which even analogue filters can't clean up the sample artifacts.  At the moment, my program uses the standard analogRead function to collect the input sound, but as I understand it, the ADC takes a few moments to stabilize or something and the analogRead function will block until the ADC flags a register saying it's ready for reading, which is wasted time that could be spent processing the previous sample.

Some people have used interrupts to control/read the ADC, but as they then busy wait in the main loop(), I have to question the wisdom of this.  I'm sure there's a reason for it (some limitation of the AtMega I'm unfamilliar with or something) but surely you'd save a lot of hassle using only loop() in the following manner:

Take value from ADC.
Tell ADC what to do.
Process the value you took.
Output the result.
Wait until ADC is ready.

(obviously the ADC would need to be told what to do and waited for in setup())

But this wouldn't need any interrupts, would maybe use less CPU power and would have the advantage of doing our processing while the ADC is working.  Can anyone explain this please?
9  General Category / General Discussion / Re: Does this look like a genuine Nano to you? on: September 14, 2011, 07:14:21 pm
Quote
Will be more careful about my sources next time because I don't like supporting counterfeiters.

Well to be factual they are not 'counterfeiters'

I'd argue if you're putting a better known company's logo and website on your product, you are counterfeiting even if the circuit itself is an open design.  Linen is an open design really but if you print dollar graphics on it you're counterfeiting.
10  General Category / General Discussion / Re: Does this look like a genuine Nano to you? on: September 14, 2011, 06:43:59 pm
Well I tried it, and it works fine.  The LED colours are completely random without any real pattern, rhyme or reason.

http://i.imgur.com/3mn8M.jpg
Just a little perfboard DSP.

Will be more careful about my sources next time because I don't like supporting counterfeiters.
11  General Category / General Discussion / Re: Does this look like a genuine Nano to you? on: September 14, 2011, 08:28:58 am
Thanks for the confirmation.  I've emailed Gravitech informing them of who I bought it off, listed the mistakes and asserted that it is sold with their branding and logo.
12  General Category / General Discussion / Does this look like a genuine Nano to you? on: September 14, 2011, 06:54:32 am
My Nano arrived today and I have concerns.  This is a real one, taken from this very site:

This is what arrived today:

Observe:
  • PX instead of RX
  • RST switch is poorly aligned
  • Several of the pin labels have been moved slightly to accomodate larger solder pads
  • It says arOuino left of the reset switch
  • The website is misaligned
  • Though not pictured, the components on the reverse are arranged differently.  Possibly a 168/328 difference but I doubt it
  • The LEDs are all labelled

I've contacted the seller with my concerns but I can't leave anything other than positive feedback for another seven days!  Seller is "lejclip", one of the first results for Arduino Nano on eBay and quite a large account.
13  Using Arduino / General Electronics / Re: Hot LEDs on: September 11, 2011, 06:35:08 am
@nexekho

According to calculations... NO nut suppose to get hot.

Well the official sensor bar does so I'm not sure what your argument is here.
14  Using Arduino / General Electronics / Re: Hot LEDs on: September 10, 2011, 08:02:15 pm
I'd imagine they're supposed to get hot, the ones in the official sensor bar get very hot even through the case.  IR LEDs are usually only used for short bursts in the case of remote controls.
15  Using Arduino / General Electronics / Re: Grounding in portable devices on: September 10, 2011, 05:00:12 pm
It's rather wise to be well grounded in the foundations of electronics.
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