ArtNet is quite easy to implement - I wrote a network protocol suite for it a few years back for a lot of the applications we have been developing. The protocol doc is available from Artistic License's website.

Might I suggest looking at much simpler-to-implement controller (such as the ARM7 series) controllers from Atmel? These have on-board flash and a wealth of SoC peripherals, so an Ethernet-connected implementation only requires the micro, PHY, and transforming magnetics - literally only two chips and a handful of passives to get going. The Atmel Devkits are also cheap.

If you're just planning on going ArtNet, you could also save yourself the time and trouble and just get an ODE from ENTTEC (http://www.enttec.com/index.php?main_menu=Products&pn=70305&show=description&name=ode) for $249 which will do the ArtNet to DMX Conversion for you and work right out of the box. These boxes are just as capable as most of the Artistic License products (with a few limitations, like no RDM) but for about 1/4th the cost.

Good luck with your Quad. The great thing about those machines is that they are such ubiquitous work-horses that you can find spare parts and service galore for them. If you are totally stuck, drop me a line and I'll get you in touch with my local guy who resells and services them all the time.

The Mod5270 will allow me to drop all the existing code in with little modification, which is nice as I quit counting lines at 5000. What I'm trying to do here is teach my existing code how to listen to DMX512 data. Doing it with my current itty bitty mcu would be more work than it's worth, as there is no way to get the UART to work at 250Kbps. I'd have to get an external UART and hook it up with SPI -- no address or data pins out on my little 40pin modules (Mod5213). While possible, it is a lot of work and free time is limited nowdays.

But if I run Vixen, throw the DMX data over the ethernet to it, then I have massive expansion possibilities. Say, in the future, running things wirelessly and having deliverable lights for every house in the neighborhood -- just plug them in and the whole neighborhood joins in with my fun. I would certainly want a cheaper chip for that expansion, but that's years away. Right now, I just want the nextGen system to run my current code, and switch to a Garbage In Garbage Out mode when it sees DMX512 data coming in on the ethernet.

And like I said, I've been wanting to play with net on the mcu's anyway :) Not sure about how easy Atmels are, but we tried to use one back in 99 and they would not give us the littlest bit of assistance when we asked for it. As the Arduino's are all Atmel, that may be different now. But moving from the coldfires would be extra work, and I've had nothing but good from Freescale and Netburner.

Oh, so you're trying to *decode* DMX and not generate it. Gotcha. I would be really, really surprised you can't your the micro to do it - I've used some of Atmel's smallest 8-bit AVR devices (the smallest that a UARTd, anyway) and they'll all do DMX just fine with at least an 8Mhz clock applied. A 32-bit processor running at 66Mhz should have no problem with this, or is it just a problem with dividing down the clocking properly for the UART? There should be multiple options for prescalars, but I suppose if you're constrained by the board hardware that might be a problem. :)

Arduino seems to just wrap the AVR chips with a slightly nicer environment, but the parts are pretty simple to use stand-alone; I have been using gcc and Eclipse for development and haven't had any issues. The Atmel ARM7/9 parts are a bit trickier, as the toolchain setup is far from straight-forward if you're trying to go the free route.

Seems like you have all well in hand! Let me know how things progress! And share some vids of your stuff soon! :D :D

Nothing simpler!

http://youtu.be/Rfu_x8sSPUo

The arches turned out to be too fragile. I'll need to mod them considerably before I try them again. But fundamentally the idea works. About 100$ in lights, wires and piping.

Something I'm going to toy with for next year is gluing silver sequins onto a plastic cylinder and rotate it about 1 rpm while shining a nice 100W halogen spot at it. Tada, snow falling white dots shining onto the wall of the house.

Yes, I'm trying to decode. And if I could get the UART to cooperate, I'd be taking the cheap route and just buying a differential reciever :) But since the built in UARTs don't come anywhere close to that bitrate, I'd be spending a lot of time getting a SPI connected receiver to work. Achievable, yes. But moving to ethernet is less taxing and permits me to do so much more stuff in the future than just this one trick. Granted, I will also need to eventually have a second universe and a device giving DMX512 differentials out, dedicated to animatronix. But baby steps first. :) ( I have a vision of two skeleton pirates in bathtubs with cannons made from air bazookas. Have a motor release mechanism and a small smoke machine that fills the air bazooka while it's back. Release it, and you make a moderately moving smoke ring "cannon shot" that travels halfway over the yard. The two pirates would trade bad pirate jokes and insults while shooting each other at the end of each other scene.)

Well, the main advantage with DMX512 is the idea that the cost-per-receiver is *incredibly* low - you're talking only a few bucks in parts in small quantities for a micro and RS485 diff transceiver that fit in the area of a postage stamp. Ethernet is nice, but the main point of ArtNet is transport of the DMX data over network, and then decode the stream out to a bunch of super-low-cost receivers via the 485. You may want to consider doing it for the head-end, and then exploring an AVR or PIC solution for your DMX decoding at each "fixture", such that might be driving your Allegro parts. Just a thought! :D

btw: I figured out a tweak to the clock which should get me 250Kbps on an internal UART. While I can't get the correct clock at 66Mhz, up the PLL to 80Mhz and I can. But that would lose my 115.2Kbps port for debug and upload. I'm also unsure my old modules can run at the higher frequency, though I'm curious now. The new parts can be purchased up to 80Mhz -- I have half a dozen that are easily 3 years old though.

Well, remember that a certain amount of error is acceptable due to the asynchronous nature of the UART - you just need to ensure there's enough marking time after the stop-bit to allow the receiver to pick up and resyncronize especially if the baud rates are not perfect. DMX is a bit less forgiving in this respect since most controllers will dump it out at 44fps with the absolute tightest timing between bytes in order to allow for the highest data rates. You can run in to some big trouble if the baud rates are not really dialed in, especially due to the back-to-back byte transmissions. At very least try to get it going for 250k as tight as possible, and then drop your debug port speed down to a low enough baud rate where the baud rate error misalignment is only a few % or less and it should work just fine. :D

True. Something I'm going to play with at some point. Watch me cook a part :)

But can you cook *ON* a part? Get a big QFP part and perhaps some little tiny eggs and micro bacon. Can we get a teflon-coated part so the food doesn't stick? :D

Any special plans for FF or the variety show?

I have nothing for the variety show, no. If you need puppet support, let me know. I have the same stuff as last year plus a few new skits. And hopefully we won't have the problems this year that we had last year.

Of course you won't, I'll be there to run the electronics