Monthly Archives: December 2018

Project: Raspberry Pi Kiosk Display

Computers, DIY, Free Libre Open Source Software, Hardware, Projects

If you’ve got a Raspberry Pi lying around and you were wondering about what you might do with it, consider using it to drive a presentation kiosk.

This post doesn’t describe how to set up a Raspberry Pi from scratch. Getting a new Raspberry Pi up and running requires a collection of materials and a bit of time, which is the price one pays for being able to buy a $35 computer. There are a wide variety of tutorials on the web describing how to make that happen, including this YouTube presentation by yours truly.

Assuming you’ve already got your Pi running, though, here’s how you can set up a presentation kiosk that will cycle through a slideshow.

1. Create and test your presentation using LibreOffice Impress software. You can do this on a separate machine running LibreOffice or on the Raspberry Pi itself. You’ll want to set up the slide transitions and the presentation repeat. (Also, if you’re using images in your presentation, be careful of using high-resolution images. I’ve had presentations choke to a halt when given too many high-res images to present.)

2. Using the terminal, download and install xscreensaver.
$ sudo apt install xscreensaver
This is the only way most people have found to reliably keep the screen from sleeping while you’re using your Raspberry Pi in a kiosk mode. Once the software is installed, you can disable the screensaver in the Accessories settings.

3. The system is now effectively running as a kiosk, although you have the Raspberry Pi, the mouse, the keyboard, and a tangle of wires all over the place. To clean things up a little, get some 3M Dual Lock reclosable fastener tape and put one strip on the Pi housing and one on the back of the monitor. You can attach the Pi to the back of the monitor now, and get it up and out of the way.

4. Once you’ve got the display set up and running in a desired location, go ahead and unplug the keyboard and the mouse from the Pi. That way it will be harder for the presentation to be accidentally interrupted.

What can you use this project for?

  1. Showcasing student work
  2. A vehicle for student investigation of the Raspberry Pi or Open Source software
  3. Presenting program information to visitors at Open House or Back-to-School night

Materials

Open Sourcing

Apple, DIY, Free Libre Open Source Software, Technology & Culture

Fun story.

For my own use and as a programming activity, I wrote a little Python script that I could use as a countdown timer. (Bonus feature: I can run multiple timers at the same time. Apple iOS, I’m looking at you!)

I wanted to have a little bell that would ring at the end, and look at that, GarageBand has a little alarm bell sound! Here it is:

I was going to throw my little project up on GitHub as an example for my students; also, because I’m A Developer. I was pretty sure I wouldn’t have a problem packaging Apple’s alarm bell sound with that project. I mean, I’d already had to go to the mat with Google/YouTube about a song I’d made using some of Apple’s sound loops, and I’d done my research. At just under 30-thousand words (at that’s only for the English version) you can polish off GarageBand’s User License Agreement in an easy afternoon, and here’s the good news about GarageBand projects:

H. GarageBand Features and Support.
Except as otherwise provided, you may use the Apple and third party audio loop content (“Audio Content”), contained in or otherwise included with the Apple Software, on a royalty-free basis, to create your own original soundtracks for your video and audio projects. You may broadcast and/or distribute your own soundtracks that were created using the Audio Content…

Cool! Oh… but wait….

…however, individual samples, sound sets or audio loops may not be commercially or otherwise distributed on a standalone basis, nor may they be repackaged in whole or in part as audio samples, sound libraries, sound effects or music beds.

Dammit, Jim. I can’t use that file in my project. Oh, and maybe I just violated the license by embedding that file here.

What should I do for my project? Quick fix: borrow a desk bell from the Theater Department at school, record a single “ding!” and process it using open source Audacity (“Screw you, GarageBand.”), et voila:

My project–including that alarm bell!–has been posted on GitHub: https://github.com/rwhite5279/timer . Mischief managed.

For the record, I totally get why the GarageBand license agreement would restrict redistribution of files. It’s just another in a long list of Apple-related frustrations for me and I needed to vent a little.

Plus, I wanted to play you my bell recording. I’m quite proud of it! ;)