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46  Using Arduino / Microcontrollers / Are there any one-click tools that could be used to update firmware via usb? on: June 15, 2014, 05:34:08 pm
Hey guys,

The Arduino micro and DUE both have a USB port for programming.  I am looking at designing a board with an Xmega using the Xmegaduino IDE which would also have USB. 

I need to be able to allow my end users to upload new firmware in a simple manner.  Right now, I've got a board with an Atmega1284 and I have them put a .bin file on an SD card and the board loads it from there.  I was thinking USB might be a better option, especially if I can make it so the board acts like a mass storage device normally so they can just drop files onto the SD card. 

So, what I was wondering is is there some utility out there which I could tell my end users to download which would allow them to simply plug the device in, select a file, and click a button to upload a binary to it?  I'd prefer not to have to do something with a batch file.
47  Community / Products and Services / Re: The Zero is upon us! on: May 21, 2014, 11:03:42 pm
Another video on the board has been posted by HackADay:
https://www.youtube.com/watch?v=SxpscquBIo4

So, what I gather from this is:

- The debugger is primarily for use with Atmel Studio.  they made no mention of debugging in the Arduino IDE.

- The SWD pins on the right side (unpopulated by default) are for using the board as a debugger when developing your own projects using the SAMD21.  I assume it plugs into the JTAG pins on the target board.

- The SPI port is not used for programming.  Presumably it is pin-compatible with the ICSP port, since it is in the same location. 
48  Community / Products and Services / Re: The Zero is upon us! on: May 20, 2014, 12:50:05 am
It seems silly to go to so much trouble.  Why would I want to use STM's debugger chip with another vendor's hardware?  I'm sure I can buy a JTAG debugger from Atmel for a reasonable price.  And I'm guessing there are open solutions out there that will work with any Arm chip.  So why be difficult about it?  You don't need to lock me in with custom chips and encryption.  Atmel has locked me in with their excellent documentation, their excellent Atmel Studio, their inexpensive ISP programmer, and all the libraries available for the Arduino.
49  Community / Products and Services / Re: The Zero is upon us! on: May 19, 2014, 01:06:41 pm
I don't like the inclusion of a second chip for debugging which won't be available for use in our own designs

What are the details on this? Are you sure the second chip won't be generally available?

I'm pretty sure.  There was a whole thread about it on AvrFreaks.  I believe one to the Atmel representatives said it was custom silicon, and that even if you reverse engineered it it would do you no good because it won't be made available for purchase.

Quote
If so, will this be the first Arduino that can't be cloned?

Yes, in the sense that you can't make an exact clone of it which features the built-in debugger. 

You should however be able to create boards which are otherwise identical, and program them. 

But you may not be able to use whatever debugging environment they add to the Arduino IDE.  Then again, it may be possible to buy a JTAG debugger from Atmel and still interface that with the IDE as you would when debugging the Due in Atmel Studio.  The debug chip on this board may in fact be the same chip in their standalone debuggers, and since it's connected via the JTAG interface, one of their standalone debuggers connected to a board with a SAMD21 processor on it may just appear to the IDE as an Arduino ZERO.  Or not.  We don't know yet.
 
50  Community / Products and Services / Re: The Zero is upon us! on: May 18, 2014, 06:17:00 am
Atmel interviews Massimo Banzi about the ZERO:
https://www.youtube.com/watch?v=6st9ym0a6Sk
51  Using Arduino / LEDs and Multiplexing / Re: Neopixels - Is it possible to do anything in the middle of an update? on: May 16, 2014, 09:38:13 pm
Ha, I just noticed all those articles on Neopixels were just posted over the last few days.  Lucky me. smiley
52  Using Arduino / LEDs and Multiplexing / Re: Neopixels - Is it possible to do anything in the middle of an update? on: May 16, 2014, 09:28:43 pm
Hm, it seems that page does have the answer:

Quote
Q: I have some interrupt timing sensitive code that I have always wanted to run while also driving NeoPixels. Are you saying this might be possible?
A: No problem! As long as you can keep your interrupt service shorter than ~5us, you can leave interrupts on almost all the time while driving your NeoPixels. The only place where you need to turn them off is during the very brief moment when sending a 0-bit pulse to make sure that it stays below the maximum T0H length. If you add the following code to protect the sending of the 0-bit in sendBit() …

I'm not certain that my audio interrupt is less than 5us, but I did calculate there's 45us between samples, so... maybe it will work?
53  Using Arduino / LEDs and Multiplexing / Re: Neopixels - Is it possible to do anything in the middle of an update? on: May 16, 2014, 09:17:16 pm
Hm, I found this interesting page:
http://wp.josh.com/2014/05/13/ws2812-neopixels-are-not-so-finicky-once-you-get-to-know-them/

I'm still reading through it, but it may hold the key...
54  Using Arduino / LEDs and Multiplexing / Neopixels - Is it possible to do anything in the middle of an update? on: May 16, 2014, 09:06:08 pm
I have a board where I'm playing audio at 22khz and I'd like to also update a short string of Neopixels (less than 10).  I've only got 45 microseconds between each sample, and I have to transmit 16 bits to my DAC every time, so I may not even have the 30 microseconds between each sample required to send one full pixel's worth of data.

I was looking at Adafruit's tutorial here:
https://learn.adafruit.com/adafruit-neopixel-uberguide/advanced-coding

And clearly, I can't hold the line low at any point for longer than 50us or the data will latch into the pixels. and the next bit of data I send will go to the first pixel. 

However, I'm wondering if perhaps I could hold the line high longer than usual, and what will happen if I do.   

For example, is the pixel keying off the length of the low signal after the high signal to decide if a bit is 0 or 1, or is it keying off the length of the high time, and the length of the low after that doesn't matter as long as it's not so long (50us) that it causes the pixel to latch the data?  Does it only decide what bit was sent after the low signal goes high again?  It seems like it would because otherwise it might load a new bit when the intention was to latch the pixel.  I guess I should look at the Arduino lib and see what they do at the end of the data transfer... either they take the signal high like the datasheet shows at the end, then go low for 50ms, or they'd just hold it low after the last bit was transmitted, which would probably mean the high time is how it decides what bit it was.

55  Community / Gigs and Collaborations / Re: Need a freelancer to help build an array of LED strobes on: May 16, 2014, 09:35:11 am
If it's a paid commission, I'm definitely interested.  I'm located in southern New Hampshire. 

I have some experience with strobes:
https://www.youtube.com/watch?v=iQdRjXtXgdg

At 1:45 you can see a 3W led strobe fire off.  Whether that would be bright enough for you with 24 of them going off at once, I'm not sure, but the video doesn't really do it justice, and it wouldn't be a problem to use higher wattage LEDs if necessary.

My email address is scswift@gmail.com, feel free to get in touch.
56  Community / Products and Services / Re: The Zero is upon us! on: May 16, 2014, 05:16:38 am
I don't like the inclusion of a second chip for debugging which won't be available for use in our own designs, and while I understand why Atmel would want to promote their new chip, and like the small package, I'm disappointed that they've announced this before the chips are even available. 

I use the Arduino for commercial ventures, and if the necessary chips to replicate it within my own designs aren't in stock anywhere in significant quantities, then this board is useless to me. 
57  General Category / General Discussion / Arduino Zero on: May 15, 2014, 09:04:33 am
So I just had this pop up in my Facebook news feed:
http://atmelcorporation.wordpress.com/2014/05/15/arduino-and-atmel-debut-zero-dev-board%E2%80%A8%E2%80%A8/

Cool!  I thought... A new 32 bit Arduino to base my own board designs around.  And the processor on it is nice and small, unlike the Due's enormous 144 pin beast.  Hm, I wonder what that QFN package next to it is?

Then I checked Digikey for stock on the chip.  BUZZKILL!   ZIP. NADA. NOTHING.

Oemstrade?  Again, ZILCH.

Hm, looks like the ZERO is living up to it's name already.  There's ZERO chips in stock anywhere!

Okay well that's disappointing...  Well maybe we could use the D20 instead?  Hm... they're compatible, and lots of those in stock... but, oh dear, those don't support USB.  The D11 then?  Those support USB and are also compatible, I wonder what they're missing... hm, before I waste my time figuring that out better check the stock...  oh for Pete's sake!  There's none of those in stock anywhere either! 

Why in the hell would they release a new Arduino based on a chip which isn't available anywhere?  I mean I get why Atmel would want to release one to promote their new chip, but this has the official Arduino seal on it and everything.  Why do we get this instead of something based on the Xmega which is widely available?  I know some have done most of the work porting the IDE to that, so it seems like a logical step to take.  I mean it's 8 bit, but it's 32mhz and at least you can get the chips. :/

Oh well, maybe in a year this will be a viable option for real products.  I doubt Atmel is gonna flood the market with tens of thousands of these chips in the next few months when Digikey doesn't even have a listing for them.
58  Using Arduino / General Electronics / Re: How many watts will this amplifier need to dissipate? on: May 07, 2014, 10:55:15 am
I found this document on Class D amplifier design:
http://www.irf.com/technical-info/appnotes/an-1071.pdf

On page 6, on the right side, it shows the equations for calculating power losses in a class D amp.

It looks like in addition to the switching losses, (which I think are constant, but I can't say for sure because I don't know what some of those variables represent) there are also the conduction losses that MarkT mentioned, which are given by:
(Rds(on) / Rload) * Pout

And, there are gate drive losses for the mosfets, which appear to also be constant so can just be considered switching losses.


Anyway, given that chart in the datasheet indicates a large drop in dissipated power as the output power is reduced, I think it's safe to say that the conduction losses are the biggest contributor here to the dissipated power, and as those do vary with the volume, a class D amp will in fact draw less current and dissipate less heat when you turn the volume down or the music is quiet.
59  Using Arduino / General Electronics / Re: How many watts will this amplifier need to dissipate? on: May 06, 2014, 01:32:48 pm
I'm guessing it's something to do with where it says "...with an inductor in series..." at the top of the page.

I dunno, that sounds to me like they were just simulating a speaker with a resistor and inductor.
60  Using Arduino / General Electronics / Re: How many watts will this amplifier need to dissipate? on: May 06, 2014, 01:30:30 pm
Here class D losses are I^2.R in the MOSFETs

What do you mean by I^2.R?  I^2 is obviously current squared, and R is resistance, but what's with the dot?
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