Raspberry Pi Remote Audio Link

Hardware for remote audio link

 

In broadcast, lots of people are still using dedicated analog lines to connect remote sites. These operate like old telephone systems: you call up the operator and request to be patched through to a specific site. They’re also rather expensive.

For a hospital radio station, [Marc] wanted to replace the old system with something less costly. The result is his Raspberry Pi STL in a Box. Inside the box is a Raspberry Pi, PiFace display, a pair of meters, and some analog hardware for the audio.

On the software side, the system uses LiquidSoap to manage the stream. LiquidSoap uses a language to configure streams, and [Marc] has a write-up on how to configure LiquidSoap for this application. On the hardware side, SSM2142 ICs convert the signal from single-ended to balanced. The meters use the LM3915 bar drivers to control the meters.

The Python script that controls the box is provided, and could be helpful for anyone needing to build their own low-cost audio link.

 

Neo Geo Arcade Gets Second Life with a Raspberry Pi

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An old Neo Geo Arcade, a Raspberry Pi, and some time were all [Matthew] needed to build this Pi Powered Arcade Emulator Cabinet.

Neo Geo was originally marketed by SNK as a very expensive home video console system. Much like the Nintendo Play Choice 10, SNK also marketed an arcade system, the MVS. The Neo Geo MVS allowed arcade operators to run up to six titles in a single cabinet. The MVS also allowed players to save games on memory cards.

[Matthew's] cabinet had seen better days. Most of the electronics were gone, the CRT monitor was dead, and the power supply was blown. Aside from a bit of wear, the cabinet frame was solid and the controls were in good shape. He decided it would be a good candidate for an emulator conversion.

We’ve seen some pretty awesome arcade conversions in the past, such as this Halloween rendition of Splatterhouse. For his conversion, [Matthew] stuck to the electronics, leaving most of the old arcade patina intact. The CRT did fire up after some components were replaced. [Matthew] ran into some refresh rate issues with the Raspberry Pi, so he opted to swap it out with a modern LCD monitor. Controls were wired up with the help of an I-PAC board.

[Matthew] had to write a driver to handle the I-PAC, but he says it was a good learning experience. Aside from the LCD screen, the result looks like it could be found in the back of an old bowling alley, or a smokey bar next to Golden Tee. Nice work, [Matthew]!

Hackaday Links: April 13, 2014

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Check out this Pokemon Yellow cartridge for Super Nintendo. Wait, what? That is a Game Boy game! Well there is a Super Gameboy cartridge that lets you play them on SNES. This mashes the guts of the two into a custom-decorated SNES cart. Now if you’re more interested in the guts of that Super Game Boy cartridge you’ll want to check out this classic hack which dumped the ROM from it. [Thanks Nick]

Here are a couple of interesting things from our friends over at Adafruit. First off, they have a high-res gallery of the Raspberry Pi compute module and carrier boards which we heard about earlier in the week. Also, the latest Collin’s Lab has a great video on soldering. We especially appreciated the discussion of soldering iron tips and their effect on heat transfer.

[Marius] got tired of the static shock from the office coat rack. You know, like the scene straight out of Office Space? But he didn’t disassemble the infrastructure to solve the issue. Instead he connected it directly to ground. Just make sure you stick the wire in the correct hole!

It’s as if Hackaday is on a quest for the most perfect DIY cyclonic separator. Here’s the latest offering which you can cut out from sheet stock by hand. It’s the alternative for those of us without access to a 3D printer.

If you think it’s too difficult to build what we refer to as a Daft Punk table you need to check out what [Dan] pulled off. He proves that your LED matrix coffee table project doesn’t have to take up a ton of time or cost an exorbitant amount of cash.

We should have mentioned this to you before the weekend so you’d have something to watch: you can now download BBS: The Documentary from the Internet Archive. We’ve watched the entire thing and it’s fantastic. If you know what a dial-up modem handshake sounds like, you’re going to be awash in nostalgia. If you don’t know the delight of those sounds you need to watch this and see how things used to be back in the day when connecting your computer to a network definitely wasn’t what the cool kids were doing. [Thanks Larry]

Create Your Own J.A.R.V.I.S. Using Jasper

JARVIS

Tony Stark’s J.A.R.V.I.S. needs no introduction. With [Shubhro's] and [Charlie's] recent release of Jasper, an always on voice-controlled development platform for the Raspberry Pi, you too can start making your own J.A.R.V.I.S..

Both [Shubhro] and [Charlie] are undergraduate students at Princeton University, and decided to make their voice-controlled project open-source (code is available on GitHub). Jasper is build on inexpensive off-the-shelf hardware, making it very simple to get started. All you really need is an internet connected Raspberry Pi with a microphone and speaker. Simply install Jasper, and get started using the built in functionality that allows you to interface with Spotify, Facebook, Gmail, knock knock jokes, and more. Be sure to check out the demo video after break!

With the easy to use developer API, you can integrate Jasper into any of your existing Raspberry Pi projects with little effort. We could see Jasper integrated with wireless microphones and speakers to enable advanced voice control from anywhere in your home. What a great project! Thanks to both [Shubhro] and [Charlie] for making this open-source.

[Read more...]

The Raspberry Pi Compute Module

Raspi

Raspberry Pi cluster computers are old hat by now, and much to our dismay, we’ve even seen Raspberry Pis crop up as the brains of a few ill-conceived Kickstarter projects. The Pi was never meant for these applications, with the very strange port layout and a bunch of headers most people don’t need. The Raspberry Pi foundation has a solution for the odd layout of the normal, consumer Pi:  The Raspberry Pi compute module, a Raspi and 4GB flash drive, sans connectors, on an industry standard DDR2 SODIMM module.

This isn’t something you can plug into your laptop (yet; that’s just a BIOS hack away, right?), but the new format does allow for some very interesting projects. All the normal Raspi I/O – CSI and DSI ports, USB, HDMI, JTAG – and a whole bunch more GPIO ports – are broken out onto an I/O board for development. The idea is that anyone can develop a product for the Raspberry Pi, create a custom board with a SODIMM connector, and use the compute module as the brains of their project.

The compute module should cost about $30/piece in quantity 100, available in June. No word yet on how much the I/O board will cost, but we expect a few open source expansion boards to crop up shortly so anyone can create a very cool cluster computer based on the compute module.

 

Powering a RPi with Hydrogen

raspberryHy

Looking for a new way to power your Raspberry Pi? The raspberryHy project aims to develop a small fuel cell designed for powering the credit card sized computer. It adds a proton exchange membrane (PEM) fuel cell, a battery, and custom control electronics to the Pi.

The system takes hydrogen in from a compressed hydrogen cartridge and feeds it through a regulator. This passes the hydrogen into the PEM fuel cell at the correct pressure, and creates a potential. The control electronics boost that voltage up to the 5 V required on the Pi’s USB port. There’s also an electronically controlled purge valve which periodically exhausts the fuel cell.

There’s a few reasons you might want to run your Pi with hydrogen. Run time of the fuel cell is limited only by the amount of hydrogen you can store. In theory, you could connect a large cylinder for very long run times. Combined with a battery, this could be quite useful for running Pis in remote locations, or for long-term backup power. The raspberryHy will be presented at Hannover Fair 2014 this month.

Raspberry Pi UPS Using Supercapacitors

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What happens when you want to integrate a Raspberry Pi into some kind of project that gets turned on and off with mains voltage? Do you power the Pi separately, or make a UPS for it?

[Lutz Lisseck] decided he wanted to turn his ambient-lamp (Rundbuntplasma) on and off with only the main power switch in his Hackerpsace. He could build a traditional UPS using a battery pack (it’s only 5V after all!) but decided to take it a step further. He picked up a pair of 50F supercapacitors. This way his UPS would last longer than his Pi would! The caps store just enough power that when the main supply is cut, a GPIO notices, tells the Pi, and it begins a shutdown sequence lasting about 30 seconds.

While [Lutz] is using two 2.7V supercapacitors, he mentions it would be a lot cheaper to use a step-up converter instead of putting them in series — but he had the caps on hand so decided to use both.

If you need it to last a bit longer, you could make one with rechargeable batteries…