Constantine Zlatev, Kostadin Ilov and Velina Ruseva have taken a disabled shotgun and some salvaged industrial components and created a musical instrument. Called The Last Gun, is controlled by a Raspberry Pi and an Arduino and uses compressed air to play different tunes through the barrel of the gun. Determining what is played is done based on a graph of US arms exports from the 1960s to 2010. If the amount of exports rises, the tune becomes more sombre; if the exports fall, a more upbeat tune is played. You can see more pictures on Constantine’s blog here and watch a video below:
This made me giggle. 🙂 Andrey Chilikin has come up with a way of automating the tea brewing process by pressing into action an old CD/DVD drive and a Raspberry Pi. They use GPIO to trigger the motor on the drive and present a text-based interface for status messages. Here’s the code and schematic should you wish to replicate this brewing sensation!
justthatoneotherdude, building on work from auntie-matter, has created a lovely, wooden jukebox with a Raspberry Pi at the centre. There are 5 knobs controlling playlists and volume and the Pi itself is running the Volumio operating system. There are ‘runner’ LEDs in a groove round the edge for extra blinkiness and you can see a build log of the project here. He’s also uploaded his code (which combines Volumio, Spotify and Dotstar software for the blinkies).
There will be a Raspberry Jam in the Meeting Room of Huddersfield Library on Saturday, 21st January. The event runs from 12-3pm and people are invited to bring Raspberry Pis and other devices along to explore and show off. There will also be some Pi workstations set-up for those without Pis. Free tickets are available here.
Yesterday afternoon, I had great fun setting up the JustBoom AmpHAT. JustBoom is a new player in the Raspberry Pi audio market, but comes from well-known company Pi Supply. I was sent the full family of JustBoom boards for review by Aaron, but I’m free to say what I want about them.
Here are the specs:
Full high quality audio – 192kHz / 32bit
2 x 55 Watt peak output at 8 ohms (2 x 30 Watt RMS)
Includes both a DAC and power amplifier – just connect to your passive speakers
Back-powers the Raspberry Pi over the GPIO (with full HAT compliant protection) at 2.5A so only one power supply required for the whole system.
Plug and play compatibility for ease of use
Hardware and software volume control from your Raspberry Pi
Onboard, hardware jumpers for configuring mute and gain settings (jumpers could optionally be changed with switches)
Mute/enable with GPIO22 (this can be overridden by using jumper J4)
No soldering required
Compatible with all 40-pin Raspberry Pis: Zero, A+, B+, 2B and 3B
Mounting hardware included
Optional IR receiver included in package
Unused GPIO pins still accessible via unpopulated extension header
This is the top-of-the-line combination DAC/amplifier board, costing £60, so I thought I’d see if it was worth it.
Equipment
To use the board, I bought a couple of speakers and a power supply. In comparison to what I could have bought, the speakers were fairly cheap (£80). I also grabbed some speaker wire so I could connect the speakers up.
I pretty much didn’t know what I was doing connecting the speakers to the AmpHAT. I knew enough, however, to make sure that the positive and negative terminals matched and the instructions provided with the speakers were clear enough.
Operating system
I installed OSMC onto an SD card and plugged it into a Raspberry Pi 3. I assumed that there was some automated set-up that would happen on first boot and, sure enough, the file system expanded and some software installed itself. I plugged in a USB pen-drive that contained some music in FLAC format (a format I knew to be of the highest quality) and selected a track to play.
Nothing happened.
Documentation
I looked on the JustBoom website for some help, but unfortunately the guides are yet to be written. I hope they get them done soon as at the moment it really is difficult to know what to do. I contacted Alex Eames (who I knew had got one of the boards working) to find out what he did, but it was a Raspbian-only solution to do with editing the Pi’s config.txt file: not an option with OSMC. So, I did a little exploring in the OSMC settings and discovered that you needed to get OSMC to load up the JustBoom DAC overlay file. I enabled this. Still nothing happened. I eventually found the setting to control where the audio was output to and selected the ALSA option. Suddenly, music blared out of the speakers, scaring the hell out of me! It worked! It worked! My first choice for music? Transformers: The Movie. For two reasons: first of all, I’ve always loved the music; secondly, I knew that it was a synthesised soundtrack with a lot of treble and a lot of bass, so I knew it would be a good workout for the system. Here is a video of the results. Please note, the sound is so much better than this – this is just on my mobile.
Opinion
So what did I think? Well, I thought that the audio result was simply tremendous. The complete sonic range of the music came through and it sounded brilliant. I appreciate this is a purely subjective opinion, but I don’t think I’ve ever heard Vince DiCola’s music with such a level of detail before.
So, in conclusion: the JustBoom AmpHAT delivers quality results once you get it working. The components on board are clearly of high quality and they’ve been put together very well. The documentation, however, is a problem – those guides need to be written as soon as possible to give a fully plug-and-play experience as it is currently not clear how to make it all work. My experience with OSMC was a bit of educated guesswork, and that’s not great for a £60 product. However, the results you get when you do get it working are… wow.
I’ve also got an IQaudIO board to test out, so I’ll let you know once I’ve got that working and can compare the two.
