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16  Forum 2005-2010 (read only) / Syntax & Programs / Re: array processing -  any shortcuts? on: January 21, 2008, 01:18:01 pm
Yeah, I was afraid it wasn't possible (or it would have been documented).

Just extend whatever your serial protocol is to contain commands that allow you to address multiple points on your matrix at once. There's no reason to have more than one serial transmission to update the entire array.

I have been doing this somewhat, creating functions to light an entire column, an entire row, all on, all off, using loops and maxOne(), maxAll() from the Zambetti 7219 code, in response to SimpleMessageSystem ASCII messages from Max.  This is probably going to be the best approach.  But since I am just getting the hang of all this I'm sure there are more efficient ways to do many of these things.

Also, I want to provide as much flexibility as possible to the Max programmers who will be building apps.  So, on the Max side I created a 'virtual stribe' represented by a large [matrixctrl] object.  Ideally the programmer should be able to write an app that interfaces with the 'virtual stribe' and it will interface with the real stribe exactly the same.  We're THIS close... but as the speeds increase (while sequentially lighting up LEDs) we're getting weird behavior.

We have an abstraction which converts changes to the [matrixctrl] Max object (LEDs on or off) into the appropriate maxOne() commands.  But if the messages come out of Max too fast, some of the messages start dropping out, and then all heck breaks loose as the LED display gets more and more out of synch with the [matrixctrl] object.  And when I also try to read the analog sensors during the loop it gets even more hinky.

The [matrixctrl] object can be made to dump it's entire state as a long string, but it seems like feeding all this data across SimpleMessageSystem would take a while...


To explain the setup: I have 16 MAX7221s, each one controls an 8x8 grid, 8 grids on the left (1-8), and 8 on the right (9-16) results in a 16x64 LED matrix.

A single 128-element array called grid[] keeps track of the 0-255 bitmask values for each subrow.

Here's the firmware right now:


What it seems like you're implying in your suggestion above is that there could be a way to send all 128 values as a single serial message?  If so that would be amazing: how would do I do this?

17  Forum 2005-2010 (read only) / Syntax & Programs / array processing -  any shortcuts? on: January 21, 2008, 11:50:06 am
Hi -

In my project I am addressing a large matrix of LEDs from Max.  I'd like to maintain a matching array in the firmware, and be able to quickly sync the two (the array with the physical LED matrix).  However looping through all the elements is really slowing things down since they all have to pass thu serial connection.  

I basically want to be able to "flash" many values into the array at once, without having to loop through the array element by element.

If someone could tell me which of these things could work (without loops), and the proper syntax, that would be of immense help:

grid[128]=255;      // Set all values in the int array grid[] to 255

grid[128]=0;         // same as above

grid[2..7]=192;     // set a subset/range of values to 192

Also, if there's any way to do math on multiple elements at once that would be great, too, e.g.

grid[128] = grid[128]-10;  // subtract 10 from all elements in the array


PS: Arduino TOTALLY rocks!

18  Forum 2005-2010 (read only) / Interfacing / Re: Can Arduino send OSC directly to Reaktor etc? on: October 23, 2007, 02:15:45 pm
Great info and thoughts, thanks!

I looked at the Lantronix stuff - I wish they made a board that would give me the Ethernet/UDP/OSC functionality via USB.

Right now I am leaning towards Freeduino/Arduino and meanwhile will wait for the technology to catch up.  I agree with your point that there is (currently) a larger community for Arduino.  Perhaps someone more qualified will solve this so I don't have to.

PS: I just picked up the new Tom Igoe book at Maker Faire Austin and it looks really great!  A lot of stuff I've had to figure out on my own these last few months is all right there in b&w.
19  Forum 2005-2010 (read only) / Interfacing / Re: Can Arduino send OSC directly to Reaktor etc? on: October 17, 2007, 02:39:09 pm
Spent some time looking at Make controller - intriguing.  I wonder what it would be like to port my current project - whether I would basically be starting from scratch.  

The Make controller seems to offer a lot of features - but I wonder if basing my project around a commercial product in general is a good idea (Arduino, Wiring, Make) because I would like to offer it as a kit.  2 sides to this - requiring a specific controller for the kit means a built-in audience, but it also limits the audience to users of that particular controller, esp if I go the Make direction, since it is the only one that offers OSC connectivity on-board...  :-/

nick: I have Tom's Physical Computing book - it definitely helped me get started but t sounds like the new one picks up where that left off.  I also see it's published via MAKE so maybe that answers my question.
20  Forum 2005-2010 (read only) / Interfacing / Re: Can Arduino send OSC directly to Reaktor etc? on: October 16, 2007, 01:27:47 pm
Maybe I can use something like this:

I found a couple of research projects where people are doing similar stuff for haptic interfaces but it seems amazing that OSC and OSC support seems to be somewhat in its infancy despite being around for several years.

Also, the Make Controller claims to support OSC - but do they just mean the OSC syntax over serial?  I doubt the Make controller provides embedded Ethernet.
21  Forum 2005-2010 (read only) / Interfacing / Re: Can Arduino send OSC directly to Reaktor etc? on: October 16, 2007, 11:59:32 am
Yeah, I've actually been talking to someone about writing me a monomeserial type driver, but I was hoping that somehow OSC really is the new MIDI.

But if I understand correctly, OSC will never work as a stand-alone protocol between machines, like MIDI, but will always require a computer?

I was imagining a little CPU or microprocessor on a card that could allow a device be recognized as a UDP client/host, but maybe that's a little too 2010.  Will do more reading on UDP before I daydream more.

...or maybe that is why Lemur/Dexter has an Ethernet port in it?  Do Jazzmutant users run a driver, too?
22  Forum 2005-2010 (read only) / Interfacing / Re: Can Arduino send OSC directly to Reaktor etc? on: October 16, 2007, 10:47:55 am
Anyone?   smiley

(don't you hate it when you are researching something online and come across your own posts in the search results?)
23  Forum 2005-2010 (read only) / Interfacing / Can Arduino send OSC directly to Reaktor etc? on: October 04, 2007, 01:03:24 pm
I am currently sending OSC (Open Sound Control) messages using Max/MSP's UDPsend and UDPreceive to control Reaktor from my Arduino.  

But I would like to be able to take Max/MSP out of the equation and talk straight to Reaktor.  Is it possible to have the Arduino send and receive OSC information natively, without intermediary software?

Also, a bonus would be to also send and receive MIDI at the same time, so the same device could be used either as a standalone MIDI controller or as a computer-based OSC controller.  Is any of this possible and if so where should I be researching this?
24  Forum 2005-2010 (read only) / Development / Re: Make a program inside arduino for a Ldr an leds on: October 12, 2008, 06:33:42 am
You have an extra "{" here:

 for(value = 0 ; value <= 255; value+=5) // fade in (from min to max)

delete the "{" above: for(value = 0....

and it should compile

25  Forum 2005-2010 (read only) / Development / Arduino vs Arduino Mini - 6 vs 8 ADCs? on: September 27, 2007, 05:13:12 pm
I recently upgraded to a Wiring board to get the 2 extra analog inputs (8 instead of Arduino's 6).  I'm working on a project that may eventually become a kit and I'd like to be able to spec the Arduino as the logic board.  I saw the great thread on how to use 4051 to multiplex analog inputs so hopefully this will be the solution and I won't have to require kit builders to buy the more expensive Wiring board just for the 2 extra inputs.

But while researching I found that the Arduino Mini has 8 ADCs.  Also, the Wiring board uses the ATMEGA128, and has 8 ADCs.  Why does the Arduino NG have only 6?  Is it a design thing or is the little 168 different than the big one?

Also, I found somewhere a spec that listed the ATMEGA168 used on the Mini as actually having 6 10-bit ADCs and 2 8-bit ADCs.  But my Wiring board (which uses the small ATMEGA128) does not seem to act differently on the extra 2 ADCs.

Can anyone clear this up for me?
26  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: spectra symbol on: February 23, 2008, 08:56:51 am
your device is the advertisement for SpectraSymbol products to which everyone else paid attention

Thanks for saying so.   smiley
27  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: spectra symbol SUCKS! on: February 22, 2008, 08:48:45 pm
I agree their site could be a lot better and more informative.  It's funny, as soon as I started building Stribes people were all like, "How did you get an in with SpectraSymbol, that's amazing."  I guess I got lucky or they liked my crazy "xenome" prototype sketches or something.  Anyways, they're here, now, so hopefully we won't scare them off.  If the demand goes up, the prices should come down.
28  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: spectra symbol on: February 22, 2008, 03:29:27 pm
I just found out about this thread and wanted to drop in my 2 cents.  I make a device called the Stribe that uses SpectraSymbol's "softpot" sensor product, and so I am probably biased, as the success of my device largely depends on my relationship with SpectraSymbol.  I also think they are really nice guys.  That said, maybe I can provide a little perspective.

When I requested my first sample packet from SpectraSymbol about a year ago, I told them what I was looking for, and they sent me a nice package of 4 or 5 different samples of sensors and membrane buttons.  One of each.  No questions asked, and it included a nice letter and a shiny brochure and datasheets and everything.

What big93 did was ask them for specific stuff: 3 of this, 3 of that, a couple of these, a pair of those.  He already knew what the sensors do and how they work, so he wasn't really getting them to "find out" if they're what he wanted - he wanted freebies.  I admit I was trying to get freebies, too, but I was happy with whatever they sent me.  In my case their investment paid off and they got a loyal customer.  big93's request sounds a lot more like a custom ORDER to me, not a humble request for samples of a very expensive product.   I think the e-mail from David Marriott was gently implying this by explaining how much it would cost him to make a "real" order.

With that many sensors, big93 could build an amazing controller and never talk to SpectraSymbol again.  Then tell everyone he got the stuff free, and everyone else would try the same thing.  Even less reason for them to send a customized free sample.

Keep in mind, 6 months ago the only way to get these sensors was through a single hobby site.  And their price?  $75 EACH!

I was thrilled with my assorted free samples, and was able to make experiments and work towards building my prototype.  Through further inquiry I found out about the softpots, and developed a great relationship with SpectraSymbol through polite and respectful communication.  They even let me order less than the minimum at first because they realized I was a little guy - but I'd convinced them I was motivated and had a real project going.  I sent them my drawings and so on.

After doing a group buy of softpots to get my own prices down, and seeing the huge interest in the product and how hard they were to acquire in small quantities, I suggested to SpectraSymbol that they try to approach some hobby sites.  I made a very strong case for DIY / hobby electronics as a fertile market.  I made the case for micro-businesses like Adafruit and Sparkfun and others.  I gave the whole speech about the modern innovator and the little guys - the DIY 'manifesto'.  Then I gave Daniel a list of sites that I thought might be interested in carrying softpots.  

I COULD have argued for becoming the sole distributor, re-branded the product as my own, and set whatever price I wanted.  Instead I vouched for this community and convinced a company that is doing just fine selling to the medical market to expand into the hobby market.  Hooray for me!  Whatever.  My point is this formerly very-hard-to-acquire product is now going to be available to everyone.

@paulb: I'm sure you're a nice guy and your intentions are good, but posting the pricing online like that... I feel it's a violation of the trust SpectraSymbol placed in you as a potential distributor of their products.  I think it makes total sense for them to set a suggested retail price for their own product based on their business model, and perfectly reasonable for them to expect you to keep your special distributor pricing confidential.

I agree with whomever suggested changing the title of this thread, as I think it reflects poorly on this community and could hurt all of our relationships with a cool little company that makes a unique and very desirable product.

BTW I think David Marriott is the President of SpectraSymbol, so you shouldn't worry about offending him by going over his head.  smiley-wink


Oh, and as far as the shipping goes the high cost is because they insure them for a lot.  The first time I held a bag of them in my hand  I was like, "I'm can't believe I'm holding $1000's of dollars."
29  Forum 2005-2010 (read only) / Interfacing / Re: wtf?  why can't I measure current? (mA) on: October 04, 2007, 09:46:30 am
Yes, that's what I meant by moving the lead.  A previous poster had it right - I had blown the fuse at some point probably by forgetting to switch the leads back before measuring some high voltage.  I have a new fuse in there but haven't had a chance to try the measurement again yet.  

Even without my amp-meter I was able to get the solution with some empirical (e.g. "screw it, let's see what happens") testing - and the 1024 leds all light up at once - w/ only USB power!  I had several very credible people telling me there was no way this would work without external power.  I think the trick was reducing the overall brightness of each matrix with a 47K resistor at ISET on the MAX7221.  Still plenty bright, though I might try some different values to see the change in current draw.

The MAX7221 datasheet recommends the 47K resistor if you are using high-power requirement leds powered externally, I guess to reduce the power requirement of the 7221.  Not sure I understand it, but hey, it works!
30  Forum 2005-2010 (read only) / Interfacing / Re: wtf?  why can't I measure current? (mA) on: September 25, 2007, 07:39:40 pm
Your comment raises a question for me - how could I NOT accidentally measure voltage if I'm putting the meter inline with +5V, but setup to read mA?

I opened it up and there are two large ceramic-looking fuses - any way to tell visibly if these are blown?  Don't appear damaged.

Update: Fortunately the meter still works to test continuity with no fuses in it - one of them tested open so that must be it.

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