Hackaday Links: April 29, 2012

More old computers on FPGAs!

[Andy] loves his Memotech MTX computer. It’s an oldie with a Z80 running at 4MHz; the perfect target for an FPGA port. The ReMemotech has everything the old one has – cassette interface and all – and can run up to six times faster than the original.

Also found in 10-forward

If you’re going to build a jukebox, why not go all out? Here’s a touch screen jukeboxwith an LCARS skin. Yep, the same interface found on Star Trek: The Next Generation.

New desktop wallpaper for you

[McMonster] found a great pair of blog posts (1, 2) showing what ancient ICs look like without their casing. Since these were CERDIP packages (two ceramic plates glued together) they were exceptionally easy to take apart leaving the entire chip intact. Pages are in Polish, but there’s a Google Translate button on the sidebar

Cheap and easy Arduino wi-fi

Quick quiz: what’s the easiest way to get data onto an Arduino wirelessly? XBees? GSM modules? Nope, just get a wireless router and an Ethernet shield. The Ethernet module only cost [Doss] $20, and we’re sure Hackaday readers have a spare wireless router around somewhere.

Chiptunes! Chiptunes I say!

[mdmoose29] has been working on making a custom SNES cartridge for a dubstep artist (tell us more, [moose]…). In his search for programming tools, he found theSNES Game Maker. We tried it out for a bit and it’s still a very unrefined beta. Still, making SNES programming easier is awesome.

You people are awesome. Here’s six things for a links post.

[Valentin] made a night vision monocular from an old VHS camcorder, a small spy camera, and a handful of infrared LEDs. Here’s a video of [Valentin]‘s build in action.

Building an Arduino Chiptunes project inside an FPGA

From time to time we find ourselves in the mood for some Chiptunes. You know, the music that accompanied all of the best 8-bit console games? These days there are a lot of projects that use the audio chips of yore to recreate the sounds, but you’re always faced with the issue of sourcing those parts. [Jack Gassett] took some inspiration from one of those projects, but solved the rare hardware dilemma by building his own Chiptunes MIDI device in an FPGA.

He saw one of our features on an Arduino controlled YM2149 programmable sound generator. He realized that you can already find FPGA libraries out there that mimic this sound generation hardware, and he’s already done extensive work with an Arduino soft processor. Why not combine the two?

He’s using a Papilio FPGA with a wing that includes a MIDI connector and audio-out jack. As you can hear in the clip after the break this sounds just like the real thing. And he’s got plans to roll as many different types of sound generating chips into the mix as possible. You know, one FPGA synth to rule them all.

[Read more…]

Conway's Game of Life in HD

We’re going to have to take [Mike’s] word for it that he built Conway’s Game of Life with high-definition video output. That’s because this screenshot is his only proof and it looks a bit fuzzy to us. But we are interested in the project which used an FPGA to generate a 1080p VGA output of the classic programming challenge.

One of the biggest benefits of using an FPGA for this application is the hardware’s parallel processing ability. For every frame of the game, the area around each living cell must be analyzed to produce the next evolutionary step. Most of the time this means processing all of the pixels in the playing area, which is the case here. [Mike] is using VHDL to program a Papilio Plus which has a Spartan 6 chip on it. He separated his code into the different components when writing about it. This makes it easy to find the chunks relating to the game if that’s what you’re interested in. If you just want to see how he implemented the VGA interface that’s well documented as well.

If you’re not familiar, Conway’s Game of Life has simple rules regarding when a cell will live, die, or be reborn. As [Mike] points out, every programmer should give it a shot at some point. We’ve seen many iterations from the very large to the very small.

Decoding, then cloning an IR helicopter toy's control signals

[Mike Field] got his hands on this Syma S107 helicopter with the intention of hacking it. After playing around with it for a while he set out to build his own infrared controller for the toy. It seems there is some protocol information about it published in various forum posts, but he decided it would be more fun to figure it out for himself.

He started off trying to capture the IR signals using Adafruit’s tutorial which has come in handy on a number of other projects. He could get his television remote to register, but not the toy’s controller. This didn’t stop fun, instead he tore open the controller and grabbed a logic sniffer to see what’s being pushed to the IR LEDs. The signals are a bit curious. It seems two different packets are sent with each command which [Mike] thinks is for use with two different models of the toy. In addition to that the frames are not synchronized. But a bit of 10 MHz sampling helped him to figure everything out, and he believes he’s got a more accurate version of the protocol than had previously been discovered. To prove it he developed an FPGA-based controller using VHDL which he shows off in the clip after the break.

[Read more…]

RFID playlists plus a QR code concept

Here’s another audio playback hack that uses physical tokens to choose what you’re listening to. It uses Touchatag RFID hardware to control iTunes. The concept is very similar to the standalone Arduino jukebox we saw on Wednesday except this one interfaces with your computer and the tags select entire albums instead of just one song. A shell script processes the incoming tag ID from the reader, populates a playlist with all the tracks from the associated album, then executes an AppleScript to launch that playlist. Check out the short demo after the break.

But what really caught our eye is the QR-code reader concept which [Janis] hopes to implement at some point in the future. The computer side of things doesn’t need to be changed, but we love the challenge of putting together an FPGA-based camera to recognize and decode the QR image. Looks like a perfect use for that $10 camera module and it’s FPGA driver!

[Read more…]

Playing MP3s from an FPGA

Building an audio player is a fun project. It used to be quite a task to do so, but these days the MP3 decoder chips are full-featured which means that if you know how to talk to other chips with a microcontroller you’ve got all the skills needed to pull off the project. But that must have been too easy for [Ultra-Embedded], he decided just to build an MP3 player out of an FPGA.

It’s not quite as difficult as it first sounds. He didn’t have to figure out how to decode the audio compressions. Instead he rolled the Helix MP3 decoder library into the project. It had already been optimized to run on an ARM processor, and since he’s using a RISC soft processor the translation wasn’t tough at all. He’s using a 24-bit stereo DAC chip to bridge the gap between the audio jack and the FPGA output. Clocking that chip with the FPGA isn’t ideal and causes 44.1 kHz audio to run 3% too slow. He says it’s not noticeable, which we believe. But if you try to play along with a song the pitch shift might end up driving you crazy.

If you’d prefer to just stick to the microcontroller based players this one’s small and inexpensive.