Open Saber Sound Project

[xl97]

I think its been stated, that adding the LED driver/control is the minimal side of this project.. so ignoring that would be 'foolish' IMHO..

I think we have had some GREAT info and help presented to us.. so we should use it. (well not me of course..but you guys) LOL

[Orthus]

I've been prototyping with a 3-axis accelerometer from Parallax, but they're too pricey. Freescale has a cheap one, but only in surface mount, which are a pain to solder. Basically, the accel gives a constant vector in the three axes due to gravity. Any motion either cancels out some of this gravity signal, deflects it, or adds to it (depending upon whether the motion is toward, parallel to, or away from the ground. The ATmegas have enough input/output pins to drive the sound output, talk to the accel, and control the reference on a BuckPuck for LED effects. Also, I'm only using the flash memory that's built into the ATmega for storing sound, so you need one with a decent amount of flash memory. This means that customizing the sound files isn't as easy as using an SD or CF card (basically, you must reprogram the chip to change sounds). From what I've done so far, powerup/powerdown takes about 1 second which equals 8k bytes at 8000hz sampling. Hum is about .3 seconds (3k bytes) that repeats, but I needed to putz around with a sounds file editor quite a bit to get the hum to not have a click at the repeat. To get teh accel to change the pitch, I must either index into a stored swing sound based upon the vector magnitude from the accel, or change the output rate of the hum data. I haven't managed to get either one working to my satisfaction yet. The first takes more memory than I have onboard, the second involves signal processing and sampling rates, which is not in my comfort zone.

[swear000]

I just wanted to show you guys this picture. It is a very basic setup and does not look expensive to build. However, it may be best to use it as a very general idea on how components can be connected:

http://www.flickr.com/photos/lodefink/2194007393/

[Banaticus]

We might be interested in a USB sound card to save room, eh?

Spending any time worrying about how the LED is going to work, how many volts we have to allot for the LED -- there were almost three pages in this thread that were spent on such peripheral material. I'd rather not see anyone get sidetracked, rather like I'm spending time on something other than sound right now.

Thanks for the great reply to your initial post, Orthos, I'll go over it tomorrow. I stopped by to drop a link off to this, perhaps it could be useful. http://en.wikipedia.org/wiki/Scheme_48

[Clockwork]

Orthus: I am surprised by the sound quality you are using. I wouldn't have thought you were achieving much better than the Hasbro you were trying to escape from. Is there a reason you haven't gone for a higher quality? Is it because of the space limitations for sound font storage?

XWing: You mentioned you had some of the Yusan (or similar) motion detectors. Did you rip these out of MRs or do you have a source on them. I am still at a complete loss to find a simple on/off motion detector. What does the Ultrasound use?

[xl97]

Banaticus -

I guess that your opinion..

but MINE (and I think many others here I believe) would like a LED driver included..

I think we had an original direction on what we wanted..but getting a correct, affordable & usable parts list was the focus now.

to 'me' it seems many of things you suggest just de-rail the original 'plan'..

To be fair.. I dont know jack about electronics really.. and I dont progam in in Assembley, Basic or C/C++.

but I was under the impression that the 'plan' was to get a an LED driver with, sensors, and sound in a small footprint package, affordable and in a 'kit/DIY' type format. (as much as it can be of course)

[Clockwork]

In general I agree with xl97. We have a current project which is to make an accessible open platform saber control board that people can assemble and program. This includes an LED driver. As the schematics are open, if one doesn't want to assemble the LED section, that is their choice. If you are only interested in contributing to the sound section, that is also your choice. All contributions are made on a "happily accepted and none demanded" atmosphere. If you want to work on a side project that adds a mechanical arm that attempts to grab your opponents saber while you duel to your saber, we will not stop you, but if nobody else is interested in it, don't expect other people to contribute to that side project.

Getting this back on track, I think the project is doing quite well. As far as parts go, for easy programming microcontrollers, I think the replicantfx is currently our interest point (although I have yet to look at the data sheet, Tim of replicantfx said he would send it along as soon as he finished making it). As Orthus has experience with the Amtel Atmega series chips, I think we should look to them as a possible chip if we want to do the development board side of things. I know we haven't talked much about amps, partially I think because the schematics are plentiful and aren't required until we get the sensor section up and running. The same goes for LED driving. I am still looking for a suitable motion detector for the basic project. I have had a look at the Yusan parts used by MR, but the website is in chinese and therefore has a large language barrier. Anyone speak Mandarin? I have also been looking for cheap and easy accelerometers just in case we can't find a suitable alternative, although I fully agree with xwing that to start with we should try and get a basic sensor, and then move up to accelerometers later. This being said, if Orthus can get his working, I think we should put them in, and encourage anyone interested (and I consider myself one of those people) in Orthus's project to help him.

So to recap, as far as I see it, for the basic version of the board we are waiting on a datasheet from replicantfx and a source on the MR style sensors. Once we can source these we can put together a schematic, build it and start testing.

[Orthus]

Orthus: I am surprised by the sound quality you are using. I wouldn't have thought you were achieving much better than the Hasbro you were trying to escape from. Is there a reason you haven't gone for a higher quality? Is it because of the space limitations for sound font storage?

XWing: You mentioned you had some of the Yusan (or similar) motion detectors. Did you rip these out of MRs or do you have a source on them. I am still at a complete loss to find a simple on/off motion detector. What does the Ultrasound use?

Partly it's space, but partly it's that 8khz sampling gives accurate reproduction of tones up to 4khz (due to Nyquist) 4khz is a pretty high tone...there's a zipped wav of a 4khz tone attached...I don't think any saber sound extends much above this. One octave above is 8khz, 2 octaves is 16khz, which is so high that you have to amplify to the point of causing pain to hear it (at least that's my understanding, too much rock-and-roll has long since prevented me from hearing up there). So you're losing less than 2 octaves of the sound spectrum by sampling at 8khz.

Most audio files are sampled at 48khz so that 20khz (the limit of human hearing) is covered under the Nyquist limit, but this is really overkill.

[Darth Cruor]

This is a brilliant idea! I'd love to take part... but I'm afraid I don't know anything about designing boards (or making them! Another thing to learn though eh? Scientia potestas est after all...), sound engineering, nothing . But still, if anyone has a job for me to do, or if they're willing to send me an email on what (or how) I can help, then count me in!

I thoroughly like open projects... and doing one on this scale, with the schematics freely available... is amazing. I saw several posts complaining about the time it would take, and next to free schematics and of course, determination, time does not even matter!

So yeah, this is great, and if there's anything I can do to help, or anything you can teach me, feel free to drop an email or pm! Good luck, and I look forward to hopefully working with you.

[Clockwork]

Darth Cruor: Glad to have you aboard! If you want to help and don't know exactly where to start why not tell us a little about yourself. Are there any skills you think you bring (I say think because I have always found people bring more skills with them than they think they do)? You have enthusiasm and that is important. Tell us what your good at, or what area you would like to start learning about and I am sure we can suggest ways you can help, have fun, and learn at the same time.

Orthus: I had a second look at the Arduino project and I can't say I wasn't interested. I am in the process of moving right now, but once I am in my new address I think I will pick up one and get tinkering with it. I like how much information there is out there. Also, judging by the possible future features I have been thinking of (RGB LED controlling and the like) I think that it could easily cover our needs in the future. Would I be correct in saying you are using the Memsic2125 accelerometer? I still want to wait and see the datasheet for the Replicantfx chip, but if that isn't suitable, or if we end up having to go the accelerometers route (as I can't find MR style sensors) then I think Arduino would be a good place to start. Do you have any experience accessing a form of memory storage using Atmel chips? Looking at the storage capabilities of the Atmega series, non seamed to have the available memory we would require to put even a single sound font (similar to a Crystal Focus sound font) on there. Obviously the formatting may be able to be optimized, I think that being able to make sound fonts easily will better for end users. You mentioned you have the Diecimila, do you think that is a good place to start?