Carl's Notes

With very few preparations, it was actually a pretty good event.

The software I was supposed to have ready for the event wasn't even complete enough to download code to the robot, or even control the robot remotely.

Despite all that, people were actually rather receptive and even fairly interested in learning about the robots we had on display.
(my concern was that since it was part of the Computing Science display, we were "supposed" to be showing programming-related things, not unprogrammed robots running default code)

The range of interests displayed by the visitors was rather intriguing.
From people who hadn't heard of the iRobot Create or the Roomba (the robotic vacuum cleaner the Create is based on) to those who had Roombas of their own, to those who were knowledgeable in the area of robotics.

At the end of the day, we even had one visitor who started a discussion among us about the current gaming consoles.

Despite how well-attended the event was otherwise, our room was fairly quiet for much of the time.
That allowed me to make some further progress on the project, but ultimately it still couldn't talk to the robot via a serial cable.
(not sure quite what the problem is even yet)

Oh well, now that the event is over, I can slow down and fill in some of the parts I skipped when I was rushing the deadline...

In related news, I'll be very tired the next couple of days due to how early I was up.

This week is kind of busy for me, especially as I had the last two weeks off for the Olympics.

1. On Monday, I have a networking homework assignment due.
2. On Tuesday, I have a computerized society paper due.
3. On Wednesday, I only have newspapers to deliver.
4. On Thursday, I have a midterm in the morning, an open house to help set up in the afternoon, my own project to demo during the open house in the evening, and take-down afterwards.
5. On Friday, I have another midterm late morning.

While I have a very busy day on Thursday, I'm most dreading Tuesday's assignment, as that's the course I'm really not liking.
(I'm much more comfortable writing in a programming language than I am writing papers in English)

---

While I'm on the topic of the open house, I may as well mention what I've been working on recently.

Last open house, I had most of the robots (about eight iRobot Create robots, basically stripped-down versions of the iRobot Roomba) running around with one of the default programs included, and one or two I had running around a program I wrote to "escape from a room", which basically meant "wander around until you find a virtual wall", though the program I wrote for it was a bit more interesting than that.

This year, I'm going to use input from a webcam as another sensor. So now I get to do stuff like finding the brightest or darkest part of the room, or chase a laser pointer.
You know, stuff that's much more interactive and interesting.

I also get my own room this year. The campus has small four- to eight-person rooms for teams to have meetings in, and I'll be given one all my own this time, with some of the Computing Science department in front of my room, and the rest in another room behind the main CS area.

So, this last week has been spent trying to figure out how to get a picture out of the webcam and into my program, hopefully in Python's Image Library format so I can do all kinds of image processing to it.

My first attempt (and what was billed as the easiest method) was using something called OpenCV, a Linux-only computer vision library.
The major problem is an issue with picture stability.
(in other words, the top-left corner of the webcam image is NOT always coming out as the top-left corner of the requested image)
This is something I'm not prepared to deal with, let alone try to understand.

So I found another alternative, and this one seems to have the advantage of being cross-platform as well.

It's called GStreamer, and it's basically a patch panel for audio and video programs.
Each element in the "pipeline" has inputs and outputs, each with their own capabilities, that can be plugged together in a large variety of ways.

Programs for streaming video from a webcam to the screen are pretty easy to find, and are fairly easy to understand, especially when written in Python.

The trick in my case was figuring out how to get the image data out of the pipeline.
(they don't like that sort of thing, so it's not terribly easy to figure out how to do, but actually doing it is quite easy)

Anyway, after a week, I've written a 30 line Python library that allows me to get a frame from the webcam reliably, as fast as I want and in the format I want.
I've tested it on a few computers (Linux only at this point) and on two different webcams, and it seems to work just fine, so it's what I'll be using for now.

The actual programs I'm going to demo aren't written yet, but that's primarily due to my other assignments with higher priority...
(they shouldn't be very hard to write, as I've done stuff similar to this before)

Near the beginning of January I wandered around the CS department on my local campus, talking with the instructors and staff I knew and seeing what might be happening for this year's open house event.

Interesting what you can get into when you know people, and they know you.

Apparently, one year an instructor used the last twenty-five hundred dollars of his grant money to buy as many iRobot Create robots as he could, and ended up with eight of them, along with all the accessories.
As they were not purchased for a particular use, they were not being used for anything, and it was wondered if anything could be done with them, and not just for the open house (which, in itself is pretty big affair on this campus).

As some of you may have guessed, I stepped up to the task and was given access to the lab and use of a laptop (so I wouldn't have to lug my 4-pounder around too much) and was mandated to provide an educational tool for programming them.
A demo of the current progress was also scheduled for the open house so we had something interesting to show.

So, over the last six to eight weeks I've written a nearly-complete Python API which, unfortunately, required that the robot be plugged into the computer to use, limiting the capabilities.
As they also came with a microcontroller to plug in the back, I also wrote a C API which was more powerful, more useful and more portable.

To test the API, I wrote a short demo program that attempted to escape from a room, using one of the Virtual Walls across the door to indicate when it escaped and the wall sensor to follow the wall once it found one.
(it was also dumb enough that it could get "stuck" on an obstacle in the middle of the room indefinitely, which was one of the things I pointed out during the open house demonstration, and asked for ideas for identifying when the robot got stuck)

Anyway, the open house had been on Thursday, and was a huge success, with the vast majority of people seeing the demo responding positively (and were also interested in some first- and/or second-year CS courses being taught with them, which may be my Master's thesis if it and I get accepted as a graduate student).

I definitely had some fun building the software and testing it, and then almost got hoarse during the open house due to the number of people to talked to.
(I'm pretty sure that I spoke to one off-campus reporter, too, in addition to our public-relations person)

The software will be made available for free under some open-source license once I figure out how to use SVN...
(man, I didn't realize how much I liked Git until I tried to use other version-control systems...)

So, yet another example of stepping in to fill some semi-useful role...

Kinda feels good, you know?

*a package appears on the doorstep of the fox/marten*

*the fox/marten peeks outside, sees the package and snatches it up, dashing back inside*

*after a few minutes, he crashes out of the front door*

"AH HA HA HA HA! Mortals! Fear the awesomeness of my creation!"

*a tiny, fragile Lego robot drives out the front door and attempts to drive down the stairs, but ends up crash-landing in a pile of small pieces at the bottom of the steps*

"Darn, I guess I should have checked the manual on this thing first..."

Well, since that didn't seem to work, I should say that I've enjoyed playing with Lego for many years now, and had got my first Lego Mindstorms kit a couple years ago from a secondhand toy fair.

I was so excited!
I could finally build and program my own Lego robots!

But the problem was that it only came with one working motor, the other had came completely seized up and wouldn't even turn by hand, let alone on command from the RCX unit (the Lego robot's brain).

However, on my last birthday my parents gave me a "gift certificate" for $50 from Lego to use as I wished.
So I carefully browsed their website trying to find a match for the motor that came with the Robotics Invention System I had, but what with it being several years old, I didn't find it on their website.

Fortunately, they still make some of them (or at least have some in stock), as I found out after not one, but two calls to Lego's Canadian phone number.
It's a darker grey, but I don't care about the colour, it'll be compatible with what I have already.

Now I can finally build a mobile robot that can actually steer without having to do that nasty turn-in-reverse thing that I had to do previously.

Once my order comes in, I'll finally be able to build robots like they describe in the books I have!


Later, once I've played around with the system I have enough, I'll probably go out and buy their new update to the system, the Lego Mindstorms NXT.
Boy, what I could do with that!
(it can use many Bluetooth-compatible devices, including cellphone cameras!)