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 #2893
Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
Hi all,
After having quite a frustrating time trying to run 8 synchronized timers on a micro controller unsuited for the task, I thought of a better way to play MIDI files into a DRSSTC.
Inside this ZIP file is a SoundFont file and a player; just drop the SF2 into the player, select your favorite MIDI file and out of your sound card, will come nice square pulses that can be buffered and sent over a fiber link.
Registered Member #2292
Joined: Fri Aug 14 2009, 05:33PM
Location: The Wild West AKA Arizona
Posts: 795
Adam,
I like the idea, my only dread is the lack of control over the PC sound card, if the OS decided to steal the card or the driver crashed you could be potentially left with some long pulses that can cause damage, are you mitigating that in any way? Potentially a micro with priority control over the fiber output being fed from a USB codec could solve that problem, but then again I'm paranoid....
Great work, I would not have guessed that an audio codec could resolve <50uS pules seeing that it's approaching it upper bandwidth usually around 20KHz.
Registered Member #2893
Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
The sound card does sample at 44,100 Hz, so I figured if I were to create a waveform with 10 "high" samples and 90 low samples, I'd get a ~440Hz waveform to play with. Adding a few bits here and there and concatenating several samples gave me a true 440Hz wavfile to play with.
SoundFonts are played at different pitches through resampling, so the ~120us pulse width for 440 becomes shorter for higher frequencies, and greater for lower ones. The idea is your "buffer" would be a schmitt-triggered adjustable one-shot which pays attention to only the rising edges.
I have not yet built that, but will have more space to screw about with my tesla coil when I move from berkeley to atherton in a month or so.
Registered Member #54503
Joined: Sun Feb 22 2015, 10:35PM
Location: New Zealand
Posts: 288
Is it possible to have software that can generate MIDI output from taking the peaks and notes of the waveform of any music being played and convert it to a signal that would play on the tesla coil?
This would be far easier than getting midi files and trying to synchronise them to a backing track.
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.
Doing away with hardware MIDI interrupters
