Re: [LAU] USB MIDI controller + OT 14-bit question

On Sun, 11 Dec 2016, termtech wrote: The controlers previously discussed (bcf2k and other MCP controllers) probably come closest. The faders are 1024 (10bit) via pitch controls. The smallest 4 bits are ignored. Which brings about the whole hi rez MIDI control question. Even with 7 bit CCs it is quite easy to make a change fast enough to skip many intermediate values. While it is still possible to make a slow enough move to use all 10 bit on the mcp faders, they are getting close to the limit of what the physical resistor/motor combination can handle... and the receiving software still has to ramp from value to value (same with a GUI slider) anyway. Otherwise there will be zipper noise. So the question quickly becomes how many bits are noticable with proper ramping. The only controller specs I have looked at with true high res in the spec are some of the Yamaha mixer controllers which have some controls with as high as 28 bits... if they are actually continuous or just a way of sending bigger numbers I am not sure (I don't have one to play with) You must have smoothing for anything MIDI. It is not woth sending 5 midi values where the last one comes after 3 midi events after you want to send the the 6th event. MIDI can only send about 1000 events per sec (10bits a byte at 31k, 3bytes per event... so 4 events per nrpn would cut that in 4. nrpns can be less if there is only one control being moved at a time. as soon as more than one move at a time, all 4 bytes need to be sent. This is why MCP uses pitch bends for hi rez control... but that limits you to 16 high rez controllers per midi port. So any application that accepts MIDI CC control does smoothing. The controller makers tend not to advertize the granularity of their controls :) because they are selling them to PNP people who use a MAC because (insert name of star here) does. All they are concerned about is that they can plug it in and it works. Most of the controllers I can think of that use hi rez info very much are OSC controllers and touch sensitive. For testing purposes a midi to midi converter middleware may take any midi controller and allow two CCs to do high/low byte work. 96 position encoders are quite common, more so than 128 position encoders. Both are cheap ($5 each or less). A 14 bit encoder is $40-$60 complete... the chip inside being about $11 and the casing/bearing/etc making up the rest. The seven bit encoder for $3 requires much more computer attention and pin out. And cpu speed matters (remember this is a controller, no one wants to spend an extra $1k for a super computer to run it... they are R-PI like deals) So there is not likely to be such controllers. It is possible that you could create a map for a touch based controller (think android) that would do what you want... but remeber your res in that case is based on the resolution of the touch screen itself, even a controller boasting .001 kinds of movements is going to send a new value every touch pixel movement. So you want a large touch screen :) This has been much of my research in the past year and a half. It is not just what the resolution of the controller is, but also how fast you can detect change and send it... and how fast the receiver can deal with it. I am quickly coming to the conclusion that even 8 or 9 bits is enough. -- Len Ovens www.ovenwerks.net