dev gadget, leap_motion


Like most people I got my hopes high when ordering this gizmo and again like most people I was disappointed by it. It’s not quite the mouse-replacement as I hoped it would be. Anyway, I mostly bought it to develop applications using it. It comes with an SDK and libraries for .NET so I cannot complain much about that. I wanted to develop something simple just to get the grasp of it. Recently PluralSight published a course for Leap Motion development and I thought it was a great chance to start my own little app: Tic-Tac-Toe. The course was very helpful and I’d recommend it as a starting point for Leap Motion development.

So there is still work needed on my TicTacToe but you can find below a sneak preview of the current version.

Basically it does what it’s supposed to do at the moment: draw things on screen using your finger! So I think I accomplished what I set out for. What I want to add is a custom gesture for X. Circle gesture is built-in to SDK so drawing circles is easy. But I implemented ScreenTap gesture for playing Xs which is not intuitive obviously. Also it requires precision because it’s not quite easy to target a cell while tapping. If you watched the video you may have noticed I missed the cell for Xs second move for example. So that would be the most improvement I can make apart from the basic things like player info, statistics, undo moves etc. But as they are not directly related to Leap Motion development they are not very important in this context.


hobby raspberry_pi, game

I used to love my Commodore 64 when I was a child. Now that we have the ability to emulate old machines and memories I decided to give it a go. Apparently creating a MAME is a popular subject. I’ve found this C64 emulator:

It’s pretty straightforward. Download the rom, burn it to an SD card using a tool (I used Win32DiskImager). Then upload your ROMs to RPi and let the good times roll!

One of my favourite games was Donkey Kong so I decided to start with that.

Donkey Kong

Donkey Kong

It loaded nice and dandy but couldn’t play it with the keyboard. So either I’m going to buy an old Joystick and figure out a way to connect it to the RPi or try to dig a little deeper to find out the key mapping.

aws s3

We all know backups are good but most of the time you won’t need a backup from a year ago. Just keep enough copies to recover from a possible failure and get rid of the rest. The other day I was working on cleaning up old security camera images which become meaningless very quickly. The images are uploaded to Amazon S3. My first approach was to delete the older ones by a scheduled script but then I discovered an easier and more effective way.

Let AWS do the work!

It’s possible to loop through thousands of objects and delete them but the alternative is to set an expiration date for each object. To activate this select the folder and make sure the properties panel is visible. Expand the Lifecycle section and click Add rule. Add a number of days for the expiration. Make sure “Apply to Entire Bucket” is checked so that any newly uploaded files comply with this rule. It’s easy as that!

S3 Lifecycle

One thing to note is that this process runs once a day. So don’t expect to get your bucket cleaned up immediately. But also don’t forget to check the next to ensure everything is working as expected!