The beginning of the new year celebration.
The food is ready, there’s music playing…
The next iteration of the HoloController is just about ready for use.
The on-board software is finally (no, really) ready to be wired up in the lab and I expect to do that tomorrow sometime.
The prototype controller is shown below with LEDs in place of connections to the relay board. I’ll likely leave those in as I’m wiring the two together so that I can clearly see that both ends are working. The lit LED below is a temporary status light that shows me the software on the Arduino is running.
The resistors are all 10K pull down resistors for input from the several switches that I’ve got on my workbench for turning laser and shutter power on/off. The 10K pot serves as a stand-in for the light sensor that sits above the table and is used to verify that the shutter opened as expected. Two voltage regulators provide 9v and 5v for various applications. I’ll be expanding their circuits soon to add diode protection and capacitor smoothing. An external board has TIP20′s for controlling the 1W LED status lights out in the hallway. At the moment they just blink or are steady-on but with the Arduino I can make them fade and add sound back back to the experience with an external piezo speaker. I miss having an R2D2 in the hallway like I did with the Lego RCX controller I started out with.
I’ve got one digital and one analog pin open so sometime soon I expect I’ll be expanding the system with more monitoring and someday with a touch screen or something similar.
The Arduino software is capable of driving the lab all by itself but since it doesn’t have a UI, I still need to use the PC to provide an easy to use input interface.
I’ve updated the HoloController software with an Arduino driver that simply sends port commands like the K8000 driver did and otherwise still controls the lab and exposures. Soon I’ll modify the PC software so the Arduino handles all the work which means the interface will move to an all-serial command set that can be more easily ported to other languages. The protocols are all written and tested now.
Woot! for Arduino!
A view of the table is available over here.
Ugh. I went to power up the table on Saturday and discovered the main controller wouldn’t come on.
At first I thought the laptop had frozen (it doesn’t this every once in a blue moon) but no, it was running just fine.
Poking around under the table revealed a slightly melted fuse cover on the main controller and a fuse with no wire at all.
The recent electrical storms had apparently tried to toast the controller.
After purchasing some new fuses I found that the recent electrical storms had succeeded in frying the controller. As soon as I turn it on the fuse blows in a spectacular way. Short in the transformer? That’s what I’m hoping.
OneNote has been written about ad-infinitum as a tool for note taking in meetings and classes, as a general information repository and as a collaboration tool but I’d like to introduce you to another use that I’m putting OneNote to.
Or more specifically, documenting both the process I go through when creating a hologram and the results from that process in the form of notes and pictures.
As most of you will probably know, OneNote is a great repository for all sorts of information. It has allowed me to combine a number of sources into one place so that when needed, I can easily refer back to previous results when I’m making a new hologram.
For almost two months now, I’ve been working to figure out the exposure and processing steps to use in order to get bright and clean transmission holograms using my Coherent 315M and VRP-M film.
After blowing through roughly 68 pieces of film (mostly 1.5×1" in size) I think I’ve finally nailed the process to use for transmission masters.
JohnK on the holography forum had asked if I’d experienced any problems with delayed development of VRP-M.Â He’s been working on making holograms using a Coherent 315 and VRP-M film and was wondering VRP-M was sensitive to delays of several hours between exposure and development.
I normally develop right after exposure but did the following test to find out how VRP-M behaves.
You know you’ve got too many balls in the air when you set up to make a hologram and forget to put the unexposed plate in the plate holder.
I had cut up a couple of pieces of film and soaked some of them in TEA while planning to expose one untreated piece.
I got all the other pieces soaked and squeegeed, took final light measurements, left the lab and started the exposure from the other room.
Everything went according to plan, the shutter opened and closed properly but when I went back into the lab to develop the film I discovered that the holder was empty.