Fear the Weasel

After a bit more looking around on the net I found another similiar design. From what I gathered it had a UV LED on one side of the string and a detector on the other and measured the 'shadow' of the string. Your right about the ambient light thing though, seems to be one of the biggest problems with the pickups design. Optical aside then, does anyone have any idea how I could convert hitting a string into usable data. Just the fact the string has been struck to start with but also to get a corrisponding 'velocity' at some point hopefully. I was thinking maybe something along the lines of using the output of a normal pickup? (would need a different pickup for each string though to distinguish) Thinking out loud.. ;)

Hi there, I stumbled upon this the other day. http://www.opticalguitars.com/ I was wondering if anyone had any ideas how it worked. I'm thinking through the idea of building something similar and I'm a bit stuck on how to do the pickups. Basically I just need to figure out how to get a velocity from the strings (not pitch). Thoughts, ideas?

Sorry, if you look back I'm actually in New Zealand, 'stryd_one' is the one who's actually in Melbourne so I'm afraid I won't be able to make it.. ;) I'm going the PIC route for this project. I figure if I can learn this sort of stuff it'll open up a whole new bunch of possibilties for me. I love making stuff..... ;D Should be getting some necessary things to start building and programming in about a week....

Wow, a few replies since I last checked, I thought this thread had died. Thanks for all the advice and links guys. I've been trawling around the internet picking up all the info I can. I'm thinking of trying to use a PIC as I'd like to learn more about this sort of stuff and I tend to learn better chucked in the deep end... ;) That USB to Serial module is also the type of thing I was looking for. Thanks guys, will hopefully get started on this in earnest in a couple of weeks.

Cheers, for the reply. Melbourne eh? I've heard only good things about Melbourne when it comes to music and art, many Wellington people I know have moved there because 'Melbourne is just like Wellington, but huge!'. :D Alright, I'm gonna look into the parrallel port stuff for a start, then PIC stuff. I've seen a few case mod sites about LCD's and I'm planning the same sort of thing with that. Another reason why I'm shying away from the Midibox for this is that although this is just a hobby project I'm working on, I've had a fair bit of interest from muso friends etc. so if I ever get everything in my head working in reality (IF) it might be feasible to sell (on a very small scale). I'm quite familiar with the 'request to sell' topic but I hardly think a midibox with 4 encoders (maybe even 2 buttons in the distant future ;D) would qualify for an 'ACCEPTED' ;). Thanks again! :) (returns to scouring the internet...)

New Zealand. :D If your getting at using a midibox to do it...surely there's a way to connect 4 encoders to a pc that's more straightforward. I'm kinda interested in learning how these things are done, midibox is cool but so much of 'the basics' is done for me, even when I get my Midibox finished (different project) I'm not really going to know much about electronics and interfacing etc, just how to build a midibox. ;) I'm willing to learn stuff myself I just need a direction, at the moment I don't have even that. Has anyone done something remotely similiar using the parallel port?

Hi there, I'm hoping to do a bit of a project, the goal being to come away with some useful knowledge basically. I want to build a very basic interface on the front of my PC. Basically just 4 encoders which can be monitored by software and converted to midi. I considered a midibox but I really think this could probably be done a simpler way. Midibox is awesome, don't get me wrong, but parts are expensive where I am and surely Midibox is an overkill for this? I've had a lot of experience coding C/C++ (barely any with hardware) so I could do any conversion to midi in software but basically I was wondering how to get the encoder signals into the pc in the first place. Something with a PIC maybe? (I really don't know at all! :) :-[ ) Basically if I get something talking to the software I think I can manage the rest. Ideas, thoughts, suggestions?

Hi there, I'm building a simple midi based metronome and I'm wondering if anyone knows of a good sound generating circuit to give me a nice clicking sound. Something that could just be fed with a pulse from a DOUT and ouput at headphone level. Even better would be if I could have a higher pitched click for the start of each measure (could be fed from another DOUT). The midibox part is pretty much done and this is all I need to finish it off. :D Thanks!

Cheers! I'm pretty new to electronics (come from a programming background) so all this extra info is gold to me. ;D

Thanks! That's sorta what I gathered from the source code but just wanted to make sure. :)

Hi there, I'm in the process of building a Midibox that uses encoders. I plan on writing my own custom C code for the project so I've of course been going through all the current source code but there's one main feature of MIOS I don't understand. Multiplexing. Coming from a software background and not a hardware one I'm having a few problems understanding the concept of multiplexing LED's. How does this work? (in a hardware sense) Is the microcontroller going through each turning it on quickly then doing the same to the next set but so quickly I can't see the difference? Just a brief explanation would be very helpful. Sorry for my hardware newbieness and feel free to laugh out loud if my explanation is way off mark..... ;) Cheers.

Cheers guys. Tried moving the soundcard power supply around, no change. I don't have another firewire cable so I can't try that at the moment but should get one soon.

Hi there. pay_c - My soundcard is an Edirol FA-101 Firewire so should expect any problems there like you would with a built in one. When the laptop runs off battery (everything else still plugged in) there is no noise at all. However when the power adaptor is plugged in, lots of noise. Kokoon - Not too sure what you mean by 'common ground'. Every thing is plugged into the same wall socket if that's what you mean. Thanks guys for the suggestions!Â

Hey guys, this isn't really to do with my Midibox I'm building at all but I thought that since a lot of you are very knowledgable about electronics someone might be able to help me out.  My current studio setup is based around a laptop but I have found that when the laptop is running off the power supply instead of battery it introduces a LOT of noise. Very obvious when plugged into a loud soundsystem. I don't really want to just run the laptop on battery during preformances as these can be quite long and very draining on the battery (lots of harddrive use). Also I'd have to charge it between souncheck & preformance etc. Surely there is a way around this, lots if people use laptops during preformances.....  Any suggestions would be very welcome!! PS. 'DIYing' a PSU is not an option. I will fry myself. ;)Â

Cheers guys. These are gonna awesome when their done.....

Hi there. I recently bought a sheet of clear Silicone with the idea of sticking it to some tact switches I have to make nice fancy looking (backlit)buttons. However I'm stuck trying to find something that will actually stick the silicone sheets together and then onto the plastic of the switch. I've tried a few different kinds of glue but after drying it all comes apart with little effort still. Would like something that would dry clear. Any idea on what kind of glue etc. I need? (people at hardware store sure didn't know :( ) Can post a pic of the pieces if not clear enough desription. Cheers guys!Â

I realise this is an old thread but I can see the merits of what Jimcook was talking about. Keys that you can use to slowly bring a sound in and out. Just happened to be looking at the E-Drum site and saw the design for the "Optical HiHat pedal". [/http://www.edrum.info/hihat.html  (half way down). Maybe something like this could be used (obviously not for many keys but...) Just thought I'd chuck something in. Could be interesting to try, unfortunately I'm a bit busy with other midibox projects.

Hi there. Sorted out the problem. I had confused which pin of the voltage regulator was pin 1 so despite my multiple checkings I was making sure it was the wrong way round.  ::) Everything is reading proper voltages now. Thanks heaps for helping guys, this really is a nice community of poeple. (offering to send me new components! - Cheers Smash TV!!) To summerise prob (in case you've got the same): 9v going in, J2 reads approx 6.4v instead of 5v. - Check which way round Voltage Regulator is. Thanks guys!! Should I change the title of this post to something more descriptive in case someone is searching for same answer?

sweet as, just glad someones interested in helping. :) I got the core module as a kit from Smash TV so I'm pretty sure all the parts are the right ones. Not sure what that leaves. Faulty parts? Faulty user? ;) Checked the soldering again but all seems good.... Sigh. All part of the fun. :)

Wow, fast reply! I am getting 9v out of the supply and 9v off the connections to the board.

Hey guys, just finished my core module board and tested the voltages. Seems I am getting 6.4 Volts all round. I'm using a 9v 0.8mA DC power supply that mesures just that on J1 but at J2 I'm getting 6.4v instead of 5v so it's something in the starting stage. Checked the board visually for shorts or anything but can't see any problems. Capacitors and diodes are round the right way. Maybe I fried one of the components when soldering? Any ideas on the problem or how I could find it myself would be much apprieciated. Kinda new to this electronics stuff, just hanging out to get it all going so I can get into the programming stuff!! Cheers all!

Thanks! Hopefully over the next few weeks I'll start sorting something out. Would make a good example on using the MIOS C Wrapper I think. Cheers!!!

* FIXED PICTURE LINK ABOVE * Okay, here's what I'm thinking so far in psuedo-code. (note: this is just for one of the two LED Displays to simplify things) On Button x1  ;;Left button - decrease   If counter == 0    counter = 13 ;; wrap at each end, 14 Different values possible - see table above   else    counter-- On button x2 ;;Right button..... . . . Update LED Digits    temp_sr = 8 bit value from table (counter*24) ;;Get Data for relevant 1st LED digit  (each index of the table hold 3 * 8bit data. 3 Digits,8 LEDS)    MIOS_SR_DOUT(sregister2 with temp_sr)  ;; DOUT registers 2 to 7 will be used for each of the 6 total digits (see picture above)       temp_sr = 8 bit value from table (counter*24+8) ;;Get Data for relevant 2nd LED digit    MIOS_SR_DOUT(sregister3 with temp_sr)        temp_sr = 8 bit value from table (counter*24+16) ;;Get Data for relevant 3rd LED digit    MIOS_SR_DOUT(sregister3 with temp_sr)  Update CC Value    CCValue = ccvalue from table (counter)  ;;see post above I realise it's kinda a hack to just store the data for the digits like this (instead just of the data for each digit 0-9, then writing code to sort out what needs to be displayed) but because of the nature of the numbers used (see table in above post) I figure it's much easier to consider the 3 digits as 'labels'. Hold your breath cos here's the questions..... 1)  Would this code go in the mb64_buttons.inc file under MB64_BUTTON_Handler or as a META event? 2)  Is my table that stores the sregister values for the digits alright or should I try and integrate the LED_digits1_v1_3 code? 3)  Could I just use a pot to store the CC data in? My box doesn't use all the pots so could an unused one of these actually output the CC data? (0 - 127 in steps of (127/14) ) 4)  If above is possible wouldn't it then be not too differcult to use this value to update the LED Display when the VST changes it? 5)  Am I even on the right track here?? :) Please ask if anything here doesn't make any sense. Any hints or tips no matter how small would be of help. If I get this all working I plan to write a bit of a quick tutorial about modifying code and how I did what I'm doing, a sort of primer for people like me. ;) Cheers guys!!

*FIXED PICTURE LINK, sorry :) * Hi there everyone. I'm just trying to wrap my head around how all this programming fits together. I've done a lot of C programming before and a bit of ASM (a while ago granted) so the actual coding is not so much the issue, more how it is implemented. What I want to do: My midibox is a custom effect controller that controls a VST I have made for doing long evolving delays (prodominent in Dub music). The box actually controls two seperate effects (delay lines) which do the same thing (different sounds can be sent to each). Each effect has a 3 digit LED display which shows the delay timing information (ie. how many beats is the delay length  4, 1/2, 1/5, 1/6 etc). There are two buttons beneath this which increment and decrement this value. The output of the box just needs to be a single CC value and the display just needs to show 14 preset labels.                0   1   2   3   4    5     6    7    8     9    10     11    12    13 Display        4/0 3/0 2/0  1/0 1/2   1/3   1/4   1/5   1/6   1/8   1/12   1/16   1/32   1/64 CC  Output    0   10  19  28  37   46   55   64   73   82   91    100   109   118 (CC value = (127\14) * index number, result then rounded up) I was just thinking of putting this info into an array (like above) where the Display field would hold the 3*8 bit values for the LED digit display. The increment and decrement buttons just control the index value and wrap at each end ( <0 & >13). Is this all possible with the C wrapper? (would be much easier for me)  How would I integrate this C code into the MB64 existing code? (which files need changing etc.) Not looking for the exact code from someone, just directions as where to start writing it myself. I've been reading all the code examples and documentation for a while now but that little light hasn't quite flicked on in my head yet. :) Thanks for your time, hope this isn't too long. :)

Awesome. Cheers for that. Will be ordering straight away. ;D