Update on "DrumHead" Project - Comments solicited

[stpope]

Hello all,

I've been busy on the "MegaDrum + VST sampler" project (which I'm calling "DrumHead"), and have the core hardware configured and running. I'm using an Intel motherboard and 2.5 GHz dual-core processor with 4 GB of RAM, and an Asus Xonar 7-channel sound card. I selected a HAMI 8-inch LCD touchscreen that fits quite nicely onto the front of the off-the-shelf case I'm using (and it dirt cheap). The current configuration a generous (270W) power supply (which could be smaller) and 500 GB hard drive (which could be replaced with flash RAM for $$$).

The idea is that the front panel be all touchscreen (since the system will boot into the VST player), but that the rear panel allow the connection of a mouse, keyboard, or external CD-ROM (i.e., it doesn't look like a computer at first). I also made a holder so I can mount it on my Roland rack just like a TD-20.

The rear panel has all the trigger inputs (like a MegaDrum), as well as 6-channel output, mix input, headphone output and mix/phone levels. In addition, it has the usual computer I/O for USB (for installing software), Ethernet, MIDI, TOSLINK, etc.

The figures below show the status of the current prototype.

The last month I've been busy with another project, but did get to start working on a stand-alone RT-Linux-based VST player (based on JUCE & WINE, nice pun here) that'll play a Windows VST (such as BFD or any of the Kontakt-based drum samplers), and on the circuit board layout for a custom MegaDrum-like trigger processor that will suit my needs (like multiple hi-hats, various foot switches and CV pedals, etc.). I'll have 2 boards: one with all the I/O plugs, and one daughter card with the muxes and Atmel processor, which is connected to the PC by a serial line (faster than MIDI, and lower latency & jitter--a big goal). (At present I'm using a MegaDrum via MIDI, though.)

The hard part here isn't the main computer configuration or the trigger processor hardware, but (a) the analog I/O circuitry (getting clean sound out of the box), and (b) writing the embedded software for the trigger processing (necessary since there's no access to the MegaDrum software source code--I've asked).

If anyone has experience with either of these items, I'd most appreciate some assistance. I do have a basic input scanning loop and trigger processor running, but there's a lot more to it than that...

My (current) plan is to give away all the parts lists and plans, and also to sell the completed kits. I have a lengthy document with a competitive analysis, project/product description, etc., but am currently requiring a non-disclosure agreement to distribute (it in order to keep my options open--I hope you all understand). I've posted the list of parts and more details in the discussion on VDrumsForum (http://vdrums.com/forum/showthread.php?t=47705).

Here are the latest docs:

Updated system overview



The components plugged in and running BFD (on Windows XP)



The components in the chassis (disk & power supply on the bottom; motherboard mounted on a special jig above them)



The (repainted) touch screen mounted on the front of the chassis (see the MegaDrum at the top of the photo)



The rear panel (made by FrontPanelExpress)



Actual rear panel photo




Comments are welcome...

Stephen Pope

[dmitri]

and (b) writing the embedded software for the trigger processing (necessary since there's no access to the MegaDrum software source code--I've asked).

Very weak reasoning. MegaDrum is fully controllable with MIDI SysEx.

[Ken Forgettable]

... start working on a stand-alone RT-Linux-based VST player (based on JUCE & WINE, nice pun here) that'll play a Windows VST (such as BFD or any of the Kontakt-based drum samplers).

What is your latency like?!

[stpope]

and (b) writing the embedded software for the trigger processing (necessary since there's no access to the MegaDrum software source code--I've asked).

Very weak reasoning. MegaDrum is fully controllable with MIDI SysEx.

I'm sorry for the misunderstanding, Dimitri, and I'm grateful for all your work on the MegaDrum project, but there are a number of features I'd like to support (multiple hi-hats, continuous pedal input, foot-switch control of mapping, custom (non-MIDI) output protocol and timing) for which I'd need access to the firmware source (or a custom version developed by you).

Are you willing to license the firmware?

Stephen

[stpope]

... start working on a stand-alone RT-Linux-based VST player (based on JUCE & WINE, nice pun here) that'll play a Windows VST (such as BFD or any of the Kontakt-based drum samplers).

What is your latency like?!

Since I don't have the final version running yet, I can't measure it.

I'm shooting for the 2 msec range (a challenge).

stp

[dmitri]

multiple hi-hats

Very little demand for this but may be implemented sooner or later.

, continuous pedal input,

What is this?

foot-switch control of mapping

There are already several options for this in MegaDrum. Besides, since you have it connected to a PC permanently you have a full control of mapping at you hand and not just this. Remember SysEx?

custom (non-MIDI) output protocol and timing) for which I'd need access to the firmware source (or a custom version developed by you).

What is this?

Are you willing to license the firmware?

I look at all offers. Up until now nobody offered anything serious.

My (current) plan is to give away all the parts lists and plans, and also to sell the completed kits.

For this reason this topic is off topic even in the "Off topic" so I'll probably delete it. If you need advice on where and how to host your own forum and a website I can give you some pointers.

[stpope]

Hi again, and thank you for your response.

By "continuous pedal input" I mean using a standard guitar or synth CV pedal with a drum kit, for example to support tunable tympani.

I'd like to support foot-switch control of mapping in the firmware so I don't need to go back to the host for it.

The "custom (non-MIDI) output protocol" means that I'm hoping to use a direct connection between the Atmel processor and the Intel motherboard's 115 kBaud serial port. MIDI is very compact, but has no explicit timing embedded in the commands. I've worked on several protocols over the years that extend this so you can time-stamp trigger pulses in the firmware and guarantee very low latency jitter (i.e., fixed latency) in the playback scheduler.

About the licensing, in the past I asked about it and I thought you said you'd only be willing to share the firmware source only if "somebody buys the whole project outright." I'd like to explore it if there are any other options. As you can see form my postings, I haven't decided yet whether to make DrumHead a do-it-yourself project or to try to license it to a company. As such, I'm not in a position to offer cash up front, but I would propose a joint venture agreement and bullet-proof non-disclosure to protect both of our IP and labor.

I look forward to hearing (reading) your thoughts on this.

Stephen

[dmitri]

I'm locking the topic.