PICMIX - DIY midi DJ controller

[Skirmitt]

You have smart ideas.
I can not get out more than 10 bit resolution, that is a limitation of the PIC. Though that is a lot better than the standard 7 bit. I send out 14 bit for the pitch fader and 7 bit for the rest. On 8% 10 bit gives me 0.02 accuracy wich is good enough for me.

The bourns encoder I have is optical and has no dents at all, it is made with a solid shaft and has bearings wich give a bit of smooth resistance.

[MiL0]

Nice! Been awhile since we've seen a new build log

Quick question; where did you get the small buttons from? (not the arcade buttons) They look really nice - are they panel mounted? How much did they cost?

[Skirmitt]

Thanks

These are the buttons I used: http://www.itwswitches.co.uk/itw_swi.../?productid=28
They are panel mounted. Found them to be thrown away, the are very good quality and have good feedback. RS asks almost 10 euro for one button :eek:

[MiL0]

Found them to be thrown away? I don't understand, sorry...

Thanks for the link though - i think using small sanwa arcade buttons might be cheaper though! You can get some really small ones

[Fubar]

Prolly means the buttons he found were going to the poobin if he hadn't taken 'm.

[Skirmitt]

Yes idd, they are leftovers and had no purpose. The quality is very good. I have a strong signal with almost no need to debounce. Though, I have a HW debounce circuit just to be sure.
The arcade buttons are another story, there is lots of bouncing there, I had to add another 1uF cap to clean the signal. Now they are fine.

The basic debounce circuit is a 4.7K pull up and 100nF cap over the switch. That goes in an inverting schmitt trigger to have a good edge.

The board:



You see the main controller, a basic 7805 circuit, 3 schmitt triggers and the analog multiplexers. I everything works fine I'll make a PCB of it.

[zestoi]

I bought the encoders on eBay. They are from the brand Bourns and have 128 cpr. With software I can achieve 256 steps I think, have to test that out.
What is the resolution of a VCI-100 btw ? And how much could the midi protocol handle ?

impressive looking build if you're sending out relative midi messages for each movement, "ticks" if you like, then you're not limited to anything in midi really. and i don't see how absolute messages would make sense for a jog anyway. just send out something >= 64 for each tick when you move it forwards and something <= 63 when you move it back. should be easy to map in traktor then and fine tune what kind of sensitivity you need.

another cool thing to do would be to send out a midi message with a non-zero value as soon as it starts moving forwards and a zero one when it stops - to be mapped to pitch bend in 'hold' mode in traktor (and a matching one for moving it backwards). sending out additional message when you touch and a zero'd one when u release would be very handy too.

[Skirmitt]

I don't send out absolute messages. The way I do is the encoder way in Traktor. A note on message with value 127 for forward and 1 for backward. Works like a charm.
I did think about making them touch sensitive. Pretty easy to make but I don't think it would be a big advantage for my purposes.

[zestoi]

I don't send out absolute messages. The way I do is the encoder way in Traktor. A note on message with value 127 for forward and 1 for backward. Works like a charm.
I did think about making them touch sensitive. Pretty easy to make but I don't think it would be a big advantage for my purposes.

cool, sounds good. tho i guess u want to send out a 126 for forwards if sending out a 1 for backwards - probably makes no difference in practice tho. sending out 64 and 63 is more normal and only extending away from that if you need to increase the relative message effect for one 'tick' etc.

if u only want to use the jogs for pitch bend and cue'ing when not playing then u don't need them to be touch sensitive i guess - but having them touch sensitive opens up a truck load of other possibilities, esp with effects. u said u don't use them but u might do once u really get into the whole digital dj'ing thing and crazy midi mappings. i also come from a vinyl dj background - mixing on 1200's until pretty recently - not dvs tho.

[MiL0]

can i ask why you used that particular PIC? is it because you know how to program it more easily than say an Atmel based chip? How much does the PIC pcb cost in total?