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george miyagi
05-22-2005, 05:55 PM
Hello everyone

I am wanting to display dynamic graphics on an LED board for an art exhibition. But I seem to be going round in circles. I've been looking round the Basic Stamp site and boards for a couple of weeks and am still not too clear on:
1. what exact components i need
I've also looked at, and quite like, though they are pricey, the B64CDM range from Nexus
http://www.nexusmachines.com/Products/pdf/bifqdata1.pdf
which have controllers built into them.
or do i rather build my own matrix setup, using a LED 8x8 matrix and max7219 chips, which seems pretty scary.
I basically want to build an 8x16 dots matrix, and then migrate to something larger (64x32) - eventually building 5 of them.
or how would i go about this? what's the simplest and most cost-effective solution - i know that those two staments are inversley proportional.
Which development board should i start out with, or should i just go straight to breadboard. and what basic stamp model would you reccomend?
I'm on a mac so should i use the Keyspan USB converter, or is there something else.
My electronic knowledge is what little (and it is a little!) i can remember from school. so assume nothing. so i want to keep what i need to do down to a minimum. I also have severe time contraints.
2. can i use some other language to interact with the basic stamp (i have read of people using processing to talk to the stamp) if i have control over the serial port. And how does Wiring, processings serial comminucations sister app play into this equation http://wiring.org.co/
3. How do i acquire the dynamic data and feed it live (or semi-live) to the LEDs - the data is being generated from Flash - so i can XML/php/textfile/java to serve this data
5. Displaying: do i still need to address each pixel/LED seperately, or is there a way of animating them by some sort of screendump or other method. I've been experimenting with taking a series of gifs, then converting them to a binary series using processing, but surely there must be a more efficient way to animate.

Phew. i know, that's a lot of questions.
any help would be greatly appreciated
thanx

Chris Savage
05-23-2005, 12:59 AM
george miyagi said...(trimmed)
Hello everyone
I'm on a mac so should i use the Keyspan USB converter, or is there something else.
thanx
George,

·· In terms of USB compatibility with the Stamp modules, the KeySpan is·one·that we have had good luck with.· On a Mac you would need to install the appropriate drivers.

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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

KenM
05-23-2005, 02:58 AM
At first the MAX7219 is a little intimidating. But in reality it is not so bad at all. There are several example of its use with code in this forum.


george miyagi said...
Hello everyone
or do i rather build my own matrix setup, using a LED 8x8 matrix and max7219 chips, which seems pretty scary.

Post Edited (KenM) : 5/26/2005 12:17:13 PM GMT

george miyagi
05-23-2005, 09:26 AM
hey thanks Chris
is this the one?
http://keyspan.com/products/usb/USA19HS/

and thanks KenM
Any suggestions of board - breadboard/board of education???

tx

Chris Savage
05-23-2005, 10:41 AM
George,

·· That should work for you.· Just make sure you have the most up-to-date drivers for it.

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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

george miyagi
05-23-2005, 10:53 AM
ok thanks chris.
getting somewhere slowly...

but now i'm thinking...do i even need a basic stamp (maybe something i shouldn't be asking here, but i still want one, been oogling at them forever), as all it's really doing in essence is being a display driver. or am i wrong...?

have you had a look at the Wiring/Processing thing? Do you know whether i would be able to talk directly to the basic stamp from wiring?

Forrest
05-23-2005, 03:26 PM
You'll need some type of computer to communicate with the Nexus LED controller at 2400 baud - either a Mac or a Basic Stamp. Were you planning on leaving your Mac connected to the display the entire time? If not, then the Basic Stamp is a good choice.

george miyagi
05-23-2005, 05:23 PM
yea. will have 5 macs each connected to an LED, and connected to the net, which are each driving an individual version of the application.

allanlane5
05-23-2005, 08:33 PM
George:

Yes, this project will be MUCH easier with a BS2 (or some PIC-based microprocessor) in it. Desktop processors are good, but they don't do well at true real-time applications. The BS2 will let you have the Mac drive a serial port with commands. The BS2 will read that serial port, and then implement the command to update the lights, tell a 7219 what to do, etc.

The BS2 can do this as its only task -- and thus can do it more predictably than the Mac. And I don't really think the Mac has an interface which can drive the 7219, where the BS2 does.

george miyagi
05-26-2005, 10:03 AM
Thanks for all your help guys.
Anyone have any experience with other LED controllers other than the Max7219, which seem a bit hard to track downt in tokyo, believe it or not :)

Chris Savage
05-26-2005, 10:43 AM
George,

·· Some of the SX users have used the SX28 to drive 7-seg displays.· In fact, there's example code in SX/B in the SX/B Help File.



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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

george miyagi
05-26-2005, 10:57 AM
hey chris thanks for the info. would the SX28 be able to drive an LED matrix?
what about the 74HC595? that just gives you access to more pins, right?

Chris Savage
05-26-2005, 11:04 AM
George,

·· Both are plausible solutions...Especially if the SX is driving the 595's...There are many ways to go, and many examples out there.· It really depends on how many LEDs.· Especially how many in both directions, because it's much simpler to strobe LEDs in an 8 by x fashion.· As you expand out though it gets a little more complicated, but nothing an SX couldn't handle, and, depending on what else you need to do, even a BASIC Stamp 2p/px.


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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

george miyagi
05-26-2005, 02:21 PM
tx again chris. i've hopefully tracked down a supplier of Max7219s.
the displays will measure 32x16 LEDs, which is 512 LEDs each.

what BasicStamp kit you suggest i buy?
of should i buy the seperate components, and a development board (professional)???
tx

Chris Savage
05-26-2005, 11:11 PM
George,

·· That depends on how new you are.· If you're new and want to really familiarize yourself with the BASIC Stamp, I would recommend the Discovery Kit.· You can always add a PDB anytime.· A stock BS2 has more code examples available and works with the MAX7219 just fine.· That's one chip (MAX7219) I have good working code for.

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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

george miyagi
05-27-2005, 10:34 AM
thanks chris
which exact Max7219 do i need? been trolling through maxim site, but can't see the differenes
tx
g

Chris Savage
05-27-2005, 11:16 AM
George,

·· This is the one you need.· Link provided below.

http://www.parallax.com/detail.asp?product_id=603-00001



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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

idleup
06-03-2005, 09:48 PM
When it says that this chip can control individual LED segments when used with individual LED's does that mean each individual LED is controllable independantly? I am not sure what they mean by a segment.

I want to use an LED Matrix and create a triangle animation of it moving up the matrix.· This has proved to be challenging using a standard 5x7 matrix as it will only create bars and boxes shapes.

- Matt

Chris Savage
06-03-2005, 09:56 PM
Matt,

·· There are two basic modes to this chip.· In one mode it decodes segments for 7-segment displays.· In the other mode you have discrete control of 64 LEDs, but the brightness is not individually programmable for each LED, only the whole group.· But you can turn them on/off independently.

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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)