If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #1739
Joined: Fri Oct 03 2008, 10:05AM
Location: Moscow, Russia
Posts: 261
Well, I have really no idea where to ask this so I ask this here :) The question is - I planned to use something as a strobe or tesla coil driver to make it synchronize with music playing (not MIDI of course :) ). Before I just used to run my own program that reads spectrum data from WinAmp, takes a short part of (two in fact - one for one-shot, one for burst) it and uses it as an integrated intensity to detect fast jumps over the peak level (that falls off slowly - like WinAmp's dashes across the level meter, but coded separately to run on different ranges). That works, sometimes sucky, sometimes well - but I decided a better solution to be made. Now I'm stuck lol. The new software one was inspired by the Audiosurf game, that one really makes sence as it's beat tracking capability is awesome. However I have no idea how to code it :D The other idea was a hardware one - you run the signal through a resonance filter, then just rectify it with a diode bridge and feed to a cap via a shunt, the cap itself is shunted by a falloff resistor. Therefore, whenever you have a fast signal rise above the constantly falling peak level, the voltage on the charging shunt hits a high value so you can track it with a comparator and use it's output as a strobe to fire a coil or a strobelight perfectly on the beats.. in theory :) In reality I have no idea if this would work in any good way. So, anyone tried alike stuff?
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
The time-honoured method, dating from the invention of disco lights in the 70s, is a low-pass filter feeding into a rectifier and comparator. The peak-to-average ratio method that you described is a nice improvement on the plain comparator.
For more up-to-date methods, try searching the music-dsp email list archives for "beat detection". They have lots of discussion and example source code.
Registered Member #1739
Joined: Fri Oct 03 2008, 10:05AM
Location: Moscow, Russia
Posts: 261
Yaaay! Thanks a lot! Seems I pretty like this one:
It's pretty easy to code so I'll try making something alike in ASM, also it's short so wouldn't be tough to run it on an AVR hardware. So looks like I'll try it out on a test board.
Registered Member #1739
Joined: Fri Oct 03 2008, 10:05AM
Location: Moscow, Russia
Posts: 261
sry for dblposring, but I just have to tell this for the case anyone wants to make alike stuff. This one needs a unipolar input so it's best to integrate it into a TDA-based amp so you can use it both for coil drive and high-level headphone output to be unable to hear actual coil discharge sounds, however you can add a diode bridge instead of the shottky diode, a level shifter would go as well. The base bypass cap is required to reject any noise, the ADC pin was drawn just as a leftover of older research - actually this needs just a Schmitt trigger or a comparator. It's 5am here atm, so I had no time to assemble this nor to add the proper input jack and firmware upgrade into the coil's AVR - but the test circuit with a LED worked out perfectly - it was even capable of accurate tracking of the blastbeat parts (actually that's what I started it for).
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Musical drum-tracking hardware (or software?)
