Thursday, September 25, 2014

Wearable Computing

So a lot of you know about this one, since I posted it up on Facebook when I first got it working, but I thought it was about time I put up on blog post on it as well. I've gotten to the point where I can stream Youtube on it and a couple of days ago I watched the Legend of Korra Book 3 season finale on it, which was awesome. Also do notice it is not a self contained computer, there are wires coming down that hook into the battery, CPU and any other peripherals I need at the moment.
For now I've been using a flexible keyboard and wireless mouse for my inputs, but I've been thinking about and exploring different ways I can input text and mouse movements without being constrained to carrying a keyboard and mouse. Ideally this would be something I could you on the go, where I wouldn't need a hard surface in front of me to navigate. I've been trying out different voice recognition software that people have put into the open source community. The first few I tried talked back with a voice like a robot from the 80's. I named it Jarvis. Recently though I found an even better one, that actually does its voice recognition through Google Voice, It has a much more realistic women voice and so I can no longer use my cliche Jarvis name. It's name is Eva now. I'm currently working programs for it to do some simple tasks for me.
So this is one example of that exploration of how to apply input. I wanted to derive inputs from hand movements, but I didn't want to go the whole glove route as gloves just make my hands feel  sweaty. I considered using flex sensors or accelerometers and gyros but they just weren't in my budget at the time so instead I designed my own flex sensors using slide potentiometers, springs and bunch of pieces I custom designed and printed on my 3D printer. Its not done. I still need to attach the strings from the pots to the upper ring pieces and then connect it to a microcontroller that will act as a USB device and process the hand movements and send them out as text.
So a little bit on the construction. The board in little screen are pulled out of some huge video goggles that I bought from some company in China. I broke it open, extracted the electronics and started hacking away at parts of the PCB that I wouldn't need so that it would be more compact. I got rid of its internal power supply, its audio circuits, and stuff for the other eye and then started to wire in the connectors I would need to use it. The case is 3D printed and is a tight fit around the electronic pieces.

Sunday, June 8, 2014

Building the 3D Printer

Woo! I figured out what my password was for this old blog. But yeah, I thought I'd throw up an update on a recent project. I know my mom is always dying to see pictures of what I'm working on. So for you mom, and anybody else who is interested, here are some pictures of my recent 3D printer build.
Well to start off here are some prints I've done. These are Klein bottles. If you don't know what a Klein bottle is, its only like the coolest theoretical math object since the Mobius strip. This of course is merely a 3D representation, as the actual 2D object could only really exist in 4 dimensions. So yeah, I'm a math nerd, moving on...
On the left is a Batman Iphone case I printed, On the right is a case for my Raspberry Pi computer.
And this is a cover for the controller board on the 3D printer. It was my first full print and I watched it diligently for 3+ hours till it finished. Honestly every time I use it I just want to watch it. Partly because I'm afraid something will go wrong mid print and partly because I find it mesmerizing. Heres's a video.

Here are some pictures from the build. At the time I built it, I didn't have any tools besides a couple of kinds of pliers. It took some ingenuity at times but I was able to build it with just those.
The starting materials.
Various times during the build. I had to calibrate the stage so that its corners and center were exactly 0.1 mm from the nozzle at starting position. I don't have any measuring tools that can measure gaps with that kind of precision so I used my calipers to measure 0.1mm of pages in my checkbook and then used that to calibrate the stage. Who needs real tools? (I'll admit they do make things a lot easier)
Then I had to make the final calibrations in the electronics and motor drivers. I really don't have room in my room for a 3D printer. I would clear off my bed and use it for a workbench during the day but now that it's made I have to find a more solid place to keeps it. This last picture is a sneak peak at my next project, built with the assistance of my 3D printer.