Short version: Using an Android tablet, you can draw things on our Glass Block LED Matrix from the street, and it’s pretty awesome. Video here, photos here.
Things have progressed recently on the Glass Block LED Matrix which Chris Davis and Paul Vincent started. For a couple weeks, the code was already in place to let Processing talk to it via simple serial commands to the Arduino & ShiftBrite shield. We wanted to use the tools from Project Blinkenlights to control things over the network; while this didn’t entirely work as planned, the project offered a lot of ideas and inspiration.
The most recent addition I made was the inclusion of oscP5 to the Processing sketch to let it listen for OSC (Open Sound Control) messages. As it happens, a brilliant piece of free software already exists (Control from Charlie Roberts) which turns Android/iOS devices into control surfaces that send out OSC messages. On top of this, Control comes with a handful of example UIs, one of them being “Multibutton Demo” which provides a UI with an 8×8 button grid, sort of like a monome. (The tablet in all of the photos is running Control with that Multibutton Demo UI.)
As our LED matrix is 7×8, this UI was a good initial match. I set Control’s destination URL/port to the backend machine that was running Processing, set the sketch to parse the pretty simple OSC messages Control would send out at every button toggle, and then I was able to control what was on the LED matrix by drawing on that 8×8 grid on my tablet.
I finally got to show it off outside on Tuesday evening when it was dark, and it’s working pretty well, as the video shows.
- Making a Control UI that allows for color control. These are RGB LEDs, after all – we can control intensity and color, not just whether they’re on or off.
- Making this web-enabled. I think Control allows this?
- Fixing the glitchiness that I didn’t show in the video; something cryptic is going on on the Arduino side.
Check out the github project here and the project wiki page here.
Hodapp’s laser cut business cards are really cool, but they take ~7 minutes each to etch and cut out. I was curious if perhaps we could instead etch a business card stamp and use that to mass produce some business cards.
I did some research and found out that while Linoleum print blocks would be safe to etch, many cheaper print blocks are no longer made from true Linoleum, instead they are made with a cheaper PVC plastic. With that in mind I stopped at a couple hobby stores and picked up a variety of print blocks.
The first one I tested was the one I was most doubtful of, a greyish flexible substance which looked suspiciously like a PVC plastic. The burn tests were not very conclusive, there was no solid bright green flame, but there were spurts of green flame. It was enough that I did not want to risk it.
The second material tested is pictured above and it came through the burn test without any issues and it looked like pictures I had seen of real linoleum with a glue backing.
Using the B/W gradient pattern that Hodapp created I did several test runs to determine how much power would be needed to get a good depth. I also shamelessly stole the Hive13 logo from his project file.
The first result turned out pretty well except for a couple mundane details:
As you can see I forgot to mirror the image, and the thin line that goes around the 1 & 3 is too thin to survive stamping more than once or twice. It still stamped pretty well though:
For attempt #2 I mirrored the image and used Gimp to beef up the outline. Since I was in a rush I did not really try to make it have a super smooth outline after “growing” the perimeter of the logo. This resulted in a rather pixelated border.
Total cut time per stamp was ~30 minutes, but could probably be sped up by optimizing the cut power // speed. Also I think this stamp a fairly large stamp and smaller ones would obviously be faster to cut out.
Final stamping action:
At Hive13 we have a 5′ × 5′ glass block wall/window in our space and the first thing we thought of when we saw it was a 7 × 8 pixel grid.
We want to build a programmable full color, lo-res display using RGB LEDs.
To do this we obivously need LEDs – lots of LEDs. The brighter the better.
We could use these nice ShiftBrite modules, but we’d really rather go all out and get the ShiftBrite’s big brother – the MegaBrite.
ShiftBrites are about $3.50 each and MegaBrites are about $7.75 each. And we need 56 of them. We’ll also need some cabling to connect them all up. The cables are about $1.50 each too. Finally, we’ll need a a good power supply to power it all; that could be as much as $100.
($3.50 + $1.50) * 56 = $280
($7.75 + $1.50) * 56 = $518
All told, we’re going to need somewhere between $300 – $700 to do this. We’re shooting for $400 here. If we go over and get to $700, awesome. If we only get to $300, we’ll make do. Any funds raised here, but not used, will go directly to the Hive13 general fund.
Here’s the stuff on our shopping list:
Here’s the project page with our progress and prototypes so far:
CJDavis and I were at the hive until about 1:20 am this morning working on finishing up a second strand of LED lights for the Glass Block Matrix LED Display.
In this image we are diffusing the LED’s with a sheet of paper towel which causes a nice soft glow, however it greatly reduces the brightness. Therefore we are leaving the paper towels off even though they make for a great picture and viewing experience from inside the bathroom.
We have had some technical issues with both the RGB LEDs and the wiring system we are using. A good amount of the LED’s seem to have an issue where they will turn on even when the anode wire is not connected to anything. We are talking nothing, like it is just soldered into a proto-board. Current speculation is that either the LED’s are bad or the proto-boards are bad.
Another problem we have been having is that originally we were using Cat-5 to wire up each anode for the 8 LED’s in a column, however the current in the twisted pairs was enough to induce a current in the second pair causing issues with LEDs coming on when they are not supposed to. This is a fairly limited problem so far as the LEDs only glow faintly. In any case we are altering how we wire up future anodes.
I had some spare time down at the hive last night so I finished assembling the framework for the RGB Glass Block Matrix display. The next step is going to be to mark out where to drill the holes for the LED.
After that is done we can start soldering up the LEDs.