Thomas' blog

I came across some really cool particle games lately, all in the style of the original “Falling Sand” java applets, and I really wanted to make something like that.
So guess what, I did!

It was mostly an exercise in C++ for me, since I had never really done anything with C++’s cool features like classes, its different list types, and all the advanced memory management features in general. Up until now I used bare C for everything and didn’t really feel the need for those features, but it turned out they were really useful for this project. I use my own Particle class to manage the particle’s actions and properties, which is way more readable and comprehensible than doing something like that in C. I also use a vector for the big list of all the particles, and it was really useful, it would have been a lot harder to do it with pure C.

About the program itself, I’ll just show you the output of “./particletest -h”:

Usage: ./particletest [options]
-w             Set window size      (default: 800x600)
-s             Set particle size    (default: 2)
-h             View this help.

In-game keys:
lmb            Add particles of current type
rmb            Erase particles at cursor
number keys    Select particle type
scrollwheel    Scroll through particle types
t              Toggle faucet (current type if nonsolid)
c              Clear the screen
i              Show FPS (not avaraged)
g              Press this when stuff glitches

I think that explains itself. If you want to know what the individual particles do, then watch the video

Last but not least, here is the source code! It only depends on SDL, so make sure to the SDL development libraries.
And here is a windows (32bit) build. I haven’t tested it extensively, but it should work. It depends on SDL so I’ve packed SDL.dll with it. Just keep it in the same folder (or throw it in system32) and it’ll work.

Don’t let that title scare you

I’ve had my Arduino for quite a while now, and haven’t really done anything interesting with it besides simple input/output tests.
That changed a few days ago when I received my new HD44780 compatible LCD display. It’s a 16×2 character display with 5×8 dots per character. I really wanted to have one of these since it makes it so much easier and cooler to show output from an Arduino.

So after I connected my LCD, I toyed around with it and quickly found that in the Arduino IDE, there’s a built-in library for handling HD44780 compatible LCD’s. This made it really easy to communicate with it, but also really boring, and it wasn’t much of a challenge. That’s why I recently started looking into the AVR (The micro controller on the Arduino) assembly language, and the workings of the processor. This was really interesting because I now know so much more about the AVR micro controllers, and programming such a piece of hardware in direct machine code is just awesome.

The LCD.

I read some tutorials and especially the data sheet of the processor, and I was quickly able to light a led at the push of a button, and do other simple things. But of course, this wasn’t enough. I wanted to try to communicate with the LCD directly using assembly, and be able to write text to it. This was a hard task since debugging on this thing is near impossible, but in the end it worked out.

Here’s my code. All it does is display “LCD Test! ” on the display and loop infinitely.

If anyone wants to use it  (which I doubt ), it’s under public domain so do with it whatever you want.

The program in action.