New in this version:
You can grab it here or mosey on over to the original post for the instructions.
New in this Version:
The latest software can be downloaded here, you may also want to check out the release notes here.
How to Set the Address:
I’m going to assume you’ve built yourself a DMX I/O shield, if not, you can take a gander at the schematic and set it up on breadboard.
There are two tact switches on the shield, a ‘1′ switch and a ‘0′ switch.
If you press and hold both switches, then hit the reset button, the starting DMX address will be reset to dimmer 1. The pin 13 LED (marked as ‘ERR’ on the shield) will flash a few times in confirmation.
For other addresses, you’ll hold down either the 1 or 0 switch (but not both), then hit the reset switch. The pin 13 LED will light up and stay on. Then you’ll enter your desired address in binary, least significant digit first, by alternately hitting the 0 and 1 switch. As you enter each bit, the LED will turn off for a moment to confirm that bit was set. When all 9 bits are received, the ERR LED will flash a few times. If you make a mistake, just start over by holding down one of the switches and hitting reset.
An Example: let’s say we want a starting address of 246. 246 in binary is 011110110. You can get this number in couple of ways.
So thus far, the same process as addressing any other piece of equipment. Now, hold down the 1 or the 0 switch, and hit reset. The ERR LED will come on, signifying that we’re in addressing mode.
Now enter the above binary sequence, starting with the smallest number: hit the 0 switch, then the 1 switch, then 1, 0, 1, 1, 1, 1, 0. The LED will briefly turn off every time you hit a switch.
After all 9 bits are entered, the LED will flash several times. The board is now addressed to 246.
Another Example: Channel 131. Hold down the 0 or 1 switch, hit reset, enter 1, 1, 0, 0, 0, 0, 0, 1, 0.
Note: Once the address is set, the pins 11 and 12 may be re-assigned for any other use. That’s why I did it this way, rather than using a conventional dip switch, which would have taken up 9 pins on the board (I’d be lying if I said I wasn’t a little impressed by my own cleverness here). The pins are configured with internal pull-ups in setup() as:
digitalWrite(pin0, HIGH); //turns on the internal pull-up resistor for pin 11
pinMode(pin0, INPUT); //sets pin 11 to input
digitalWrite(pin1, HIGH); //turns on the internal pull-up resistor for pin 12
pinMode(pin1, INPUT); //sets pin 11 to input
Pressing the switches grounds them, setting the pin to LOW. So, exercise caution when using the pins for anything that doesn’t like to be grounded, is the only caveat.
Known Bug: for some reason, sometimes when you hit the 0 or 1 switch it doesn’t take. I’ve programmed the LED to turn off briefly if the bit was successfully entered, so if you don’t see it go off, you’ll have to hit the switch again until it takes. I don’t know why it’s doing this, if you have some time to wade through the logic let me know why and I’ll update the code.
The Astute Reader Will Wonder: why we don’t enter 000000000 for the first address. True, DMX addresses actually run from 0 to 511, so dimmer 1 is actually listening to dmx address 0. I’ve seen gear that takes this into account and automatically adds 1 to your desired address, and gear that you subtract 1 from your desired address. Since there doesn’t seem to be any standard, I’ve opted to let the software do it for you because it’s easier.
Breadboard is Great and All, But it’s not going to survive a six week run with actors tripping over it and that kid’s show that runs on Sunday mornings. So here’s a shield that can fit onto your Arduino and securely hold all your connections in place. It is tested and working with the dmx reception software I wrote for the Arduino.
Features:
Note: I changed the pin assignments slightly from early versions of the software to allow easier routing. Pins 3 and 4 in the software are now pins 2 and 3, respectively. As of Rev11 this change has been made, get the latest version here.
Continue reading for the parts and instructions…
New in this Release:
I’ve updated the instructions, or you can download the updated code directly here.
As always, let me know how works for you, or doesn’t.
Or, dispensing with the floor part:
The source would be 2′ long T5 fluorescents. Same perf metal material as before, although I upped the perforation size as I’m not going for a fluid organic effect here.
The lamps could possibly be supported by some kind of tensegrity scheme, which would hopefully reduce the number of wires I need to run to the top. The screen in this case would be simpler, I could probably get away with just riveting it to close it.
Mainly, it becomes a ballast problem. It would have to dim, and dimmable T5 fluorescent ballasts are outrageously expensive. Also, off the top of my head no one makes a 3-lamp ballast for 2′ T5s, so I’d be looking at 2 ballasts, or about $2-300 just on ballasts.
there are some parts that would be difficult to source, such as the 3-way support rod and the lamp sockets, but for the most part this is the simplest to construct.
Hmmm. I’m going to watch House now and drink some beer, and let this one sit for a few days.
Or, I Could Do Something Like This:
In this concept, there would be a helical-spiral perf metal screen which would act as a diffuser. The source would be an MR-16 or similar mounted in the base, pointing up. The perf screen is generated as a parametric surface governed by the following equations:
X(u,v) = cos(u)+1.5*u*sin(u)
Y(u,v) = sin(u)+1.5*u*cos(u)
Z(u,v) = .5*u*v
u ∈ [4, 15], v ∈ [1.5, 27]
Looks complicated, but the shape is just a trapezoid rolled up into a cylinder. I like the moire-interference pattern cast by the overlapping layers of perf metal, but in order to get a nice clean finish on the edges I’d have to wrap them in some kind of metal beading, as well as support the whole thing with vertical rods, and I’m not sure I can do that without welding. So the screen might end up being handmade paper or something like that.
There’s a Corner of my Apartment that is a Problem. See, my windows face north, so even on sunny days, which are rarer than unicorns here in Portland, I don’t get direct light into my rooms. During the summer, this means that my apartments stay cool during the day, which is nice. But in winter particularly, this corner is sort of dim and less than appealing. Here’s a picture of it:
The offending area of my domicile.
Leaving aside the rats nest of cables over by the stereo, which is something else on my list, you can see how this corner just sort of dies, especially at night when there’s no light coming in from the window. So, I could go to Ikea and pick something out a torchere, which is where everything else I own comes from, or I could design and build something myself. Here are the preliminary designs I’m working with:
Curved Wood Concept:
This would be a steam-bent curved plank of wood, with the source being either T2 miniature fluorescents, cold cathode, LED strips, etc. In the far right thumbnail you can see where that would live.
I think I could steam the curved plank inside a large piece of PVC pipe, as shown:
And then bending it in a jig, like so:
I’m going to work with a few other designs and see what I come up with.
Shiny and new out of the box!
Prologue: For Christmas, I received an Arduino. If you’re not familiar with them, they’re like a little computer with a lot of pins to which you can connect outputs like LEDs, servos, relays, triacs, or anything you’d want to control, as well as photosensors, switches, anything you’d want to take an input from. You write your program in the easy-to-learn Arduino environment, upload it to the Arduino board, and it’ll run your program automagically. I’m not a programmer, but less than an hour after taking it out of the box I had it blinking an LED for me. Buy one, they’re perfect for all of us who are trying to create some Theater Magic with no money or hope of getting any.
Well, Almost Perfect. There’s been a way to send DMX with an Arduino for awhile, but when I started poking around for DMX reception code, I came up with zilch. If you’re already savvy with microcontrollers and assembly code and avrdude and whatever-the-fuck-else, you probably know about this solution. Me, I look at assembly code and I just hear a dull screaming in my head, nevermind all that other stuff that I don’t know how to do either.
So I figured that a great first project would be to remedy this situation, and write a program to receive DMX on the Arduino platform. In the way of all Works in this Vale of Tears, this ended up being much more difficult and taking much longer than I initially anticipated. But eventually I figured it all out, and so here it is!
Features:
Continue to Page 2 for Download and Instructions…
