rasteri

Yeah they work great - so much better than optical encoders, and it makes positioning far more simple.

I think Mspinky can do that. Otherwise, you could hook a turntable up to the ADC pins of a PIC and use that to look for zero crossings. Then convert that to midi with a small program.

You guys seen these? http://www.austriamicrosystems.com/eng/Products/Magnetic-Encoders Looks like you basically dangle a magnet above them and they give you the absolute angle over a serial interface. I got some samples, I'll let you know how they turn out.

Sorry I haven't been around much, but I'm not really using midibox anymore. Just a quick update though, I figure ya'll might be interested. The standalone scratch code has been ported to the dsPIC, largely because I was attracted to its DSP instructions and builtin audio DAC. I'm now beginning to regret this decision, partly due to the proprietary toolchain, but mostly because none of the models with a DAC have USB support :/ I guess I'm either gunna port the code to MIOS32, or move to another PIC (24f series perhaps?) and use an external DAC (the TI PCM1770 looks rather tasty, for example). Are presoldered STM32 boards available yet? I guess that might sway my decision...

If you're still having problems I can post a hex file for you.

Mine's got 3 leads. Remember, each diode should have two leads, and there's two diodes in the package - but to make things easier the anodes are wired together. Here's a pic for ya (pinout may vary) : package.PNG package.PNG

I'm just drawing them in Inkscape. There are probably a million more elegant ways to make one, but the method I've been using is - 1) Draw a line the diameter of your encoder wheel. 2) SELECT ALL, then copy and paste in place. 3) Rotate the copy 90 degrees (forming a cross). Repeat steps 2-3 over and over again, halving the rotation angle each time (so 45deg next, then 22.5, then 11.25, etc) until you have no space left between the lines to paste. Remember - it's a quadrature encoder, so each line actually adds 4 steps per revolution. If you have 360 lines, that's 1440 steps. I really wouldn't go any less than 1048 steps per revolution TBH - that's about the minimum I could get away with without it starting to feel weird. I really gotta start putting all this on a website somewhere.

1) PIC18F4620 2) No idea. 3) Don't think so.

Not had a chance to add hi-res encoders yet (I only have intermittent internet access), but I will soon. Promise. Loving the design ademir :)

I've attached a schematic showing how to hook it up to the midibox core module. Youll also need to make the change mentioned in this post - http://www.midibox.org/forum/index.php/topic,11167.msg102850.html#msg102850 (that potentiometer is the crossfader, by the way.) scheme.PNG scheme.PNG

Sweeeet. Well the cost of each scratch wheel is probably a bit more like £50 by the time you add buttons and shit. But you can't scratch with the numark total control. Yup. Faders don't need to be very good for mixing.

That's an unbelievably cool idea, I especially like the second picture. I was going to say that the x-session's crossfader sucks for scratching, but as long as you keep the crossfaders builtin to the scratch devices, that won't matter at all. I think I'll build myself one now :)

You don't NEED an external soundcard - I use my laptop's internal soundcard all the time. Get hold of a program called ASIO4ALL, and set traktor to use it for output instead of directsound or whatever. External soundcards are a good idea in general though. I wouldn't get a surround card, they're mostly for home cinemas and stuff and might not come with ASIO drivers. I suggest you get one with four discreet outputs that you're sure will come with ASIO drivers. M-audio make some pretty good ones. The infinium looks like a GREAT option, I encourage you to try it out - I haven't had a chance yet. The only problem is it wants a 3.3v power supply, so you'll need to add a 3.3v regulator. Also the code will need to be modified slightly, but that's an easy job (I'll do it for you if you give me some ADC readings). In the long term I'll look at interfacing with the infinium's SPI port. Also infinium make a retrofit version of the product, which costs slightly more but should just drop straight in without a new regulator or code modification. http://www.infiniumtechnologies.com/downloads/20070330_3/download - maybe give that a go?

And ademir, that's very cool. Those things would make amazing jog wheels.

Yup. They're not too expensive, I got my USB->MIDI adapter on ebay for under £10. You won't need to do any programming. All you need is a midibox core module kit (buy from smashtv, get one with a preprogrammed PIC18F4620) and a soldering iron. It's connected to a PC running Traktor. I have built a prototype version that is completely standalone and is powered by batteries, but I'm in the middle of porting it to a dsPIC (for lower power consumption and cost) and that will take another month at least. Rest assured I will make details available (including source code) when I'm done.