Guitar Foot Controller Uses DSP For Audio Effects

guitar-pedal-dsp1

This a screenshot taken from [Pierre’s] demonstration of an electric guitar effects pedal combined with DSP and Pure Data. He pulls this off by connecting the guitar directly to the computer, then feeds the computer’s audio output to the guitar amp.

The foot controls include a pedal and eight buttons, all monitored by an Arduino. Pure Data, a visual programming language, interprets the input coming from the Arduino over USB and alters the incoming audio using digital signal processing. [Pierre] manages the audio connection using the JACK Audio Connection Kit software package.

In the video after the break he’s using a laptop for most of the work, but he has also managed to pull this off with a Raspberry Pi. There’s no audio input on the RPi board, but he’s been using a USB sound card anyway. The other USB port connects the Arduino and he’s in business.

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Color LED Matrix VU Meter Shows How To Use FFT With Arduino

If you’ve ever wanted to make your own VU meter but were scared off by the signal process you need to study this tutorial.

Hackaday Alum [Phil Burgess] developed the device using an RGB LED matrix, microphone, and an Arduino. You’ll notice that is doesn’t include an MSGEQ7 chip which we see in most of these types of projects. We have seen a few that use the Fast Fourier Transform to map the audio signal on the display as this one does. But [Phil’s] choice of an assembly language Library for ATmega chips makes this really simple to roll into your own projects.

The one drawback to the hardware choices made here is that there are only eight bits of vertical resolution. It takes a little creative interpretation to make this look good, but the use of color mixing really makes a difference. See for yourself in the demo after the break.

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Coin-op Sega Rally Used To Race RC Cars

Head to head video game action can’t even compare to this use of a coin-op Sega Rally game to race actual RC vehicles. Take a close look at those screens and you’ll see there are no computer graphics, just a feed for a camera on each of the toy cars.

The project was conceived for the Sapo Codebits VI conference in Portugal. The arcade cabinets had their controls connected to an Arduino, but getting video up and running wasn’t nearly as easy. After fruitless attempts to get the original CRTs to work the team ended up replacing them with functioning CRT units of the same size. The cars themselves have two camera, one on top of the vehicle’s cab and one mounted on a boom for a perspective that was above and behind the vehicle. The drivers can switch between either view. The cars were set loose in the room serving as the event’s retro gaming area and players were free to race each other wherever they pleased. Don’t miss the video clip after the break which shows off all of the fun. Continue reading “Coin-op Sega Rally Used To Race RC Cars”

Hackaday Links: November 29th, 2012

EMC2 CNC keyboard labels

If you’ve got a dedicated computer running EMC2 for CNC control you may be interested in these keyboard labels. [Rich] mentions that they use the labels for their engraver at the Connecticut Hackerspace. Just print them out and glue them in the face of the keys.

Dev board seminars and freebies

[Mike] wrote in to tell us STM is giving away samples of the STM32 F3 Discovery again. But you can also get in on some free seminars. One is an online webinar for TI’s Launchpad family, the other is for the F3 Discovery board and is being held all around the US.

Replacing batteries with USB power

[Johan] didn’t want to use batteries for the light on the microscope he uses when working with SMT parts. He added a few components with let him power the device from USB instead.

MSP430 VU meter uses FFT

Here’s an MSP430 using Fast Fourier Transform for signal processing. There’s very little explanation, but apparently this collection of FFT related material was used heavily in the project. [via Reddit]

Cell Racr

If you’re looking for a new office game you might consider Cell Racr. It pits your cellphone’s vibrating motor against everyone else’s. Just place the phone on an incline and repeatedly dial its number to advance toward the finish line.

Through Hole Plating And Milling At Home

Here’s a PCB fabrication process that makes us envious. It’s pretty darn close to fab-house quality at home. [Cpirius] is using a CNC mill and through hole plating technique to produce his double-sided circuit boards.

The video embedded after the break shows one board from start to finish. It begins with the mill drilling holes through some double-sided copper clad stock. Once the millings have been cleaned off the holes are coated with a mixture of waterproof ink and carbon. This prepares them for plating by making the holes themselves conductive. The board is then run through an electroplating process based on this guide.

Possibly the most interesting part of the process starts 52 seconds into the clip. The mill uses a conductive probe to generate a height map of the entire board. This allows it to vary the routing depth for perfectly cut isolation traces. That final routing process is pictured above.

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MariaMole – An Alternate Arduino IDE Aimed At Advanced Users

[Alex] has been working with Arduino for some time now, but always thought it lacked some features which advanced users would really find useful. He decided to devote some free time to fixing the problem and ended up coding an Arduino IDE for more advanced users. A screenshot of his work — called MariaMole — can be seen above. It is obviously different from the standard IDE, bot not so much as to scare off new users.

This is meant to complement the original IDE, so it actually uses those configuration settings as dependencies. Once running, the program allows you to have multiple projects open at once. These are managed with the tree in the left hand column and a series of tabs along the top of the code window. When it comes time to compile and load the sketch you can click one button like normal, or use the program to fine tune your compiler flags, libraries includes, and the like. It also allows for interaction through one or more serial terminal windows. We haven’t tried it ourselves, so please leave a comment with your thoughts after having given it a go.

thanks for the tip [Rodrigo].

PhatIO Uses File System To Control External Hardware

[Andrew Smallbone] wrote in with a link to his latest open source project. This is phatIO, a USB I/O device that uses a mass storage file system for control. The idea is that any operating system can manipulate files on a USB storage device. This enumerates as mass storage, and any alterations you make to its file system will result in pin manipulation on the I/O header.

We’ve long been Linux advocates and enjoy the fact that everything on a *nix system is a file. This simply extends the idea across multiple platforms. [Andrew’s] guide for the hardware gives an overview of how the system is structured. The top ‘io’ directory contains sub-directories called mode, pins, status, and a few others. Inside the directories are files for each pin. Writing to these files has much the same effect as writing to a data direction register, port register, or reading a pin register on a microcontroller.

The board is not yet in production and the github link to his hardware files gives us a 404 error. But there is code available for several software demos. After the break we’ve included video of the phatIO driving a Larson scanner.

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