[chuck-users] odd hid issue (touchpad)

Hans Aberg haberg at math.su.se
Sat Jul 18 18:30:24 EDT 2009

On 18 Jul 2009, at 23:47, Kassen wrote:

>> For recording turns, one should use a Hall sensor, like this one:
>>  http://www.globalspec.com/FeaturedProducts/Detail/BEIDuncanElectronics/9360_Rotary_Dual_Output_Hall_Effect_Sensor/73944/0
>> This is inexpensive though not USB, but netsearching for words like  
>> "USB rotary joystick Hall effect controller" may produce some  
>> results.
> For my own use I already ordered a HID development board which I  
> plan to use with a optical step-less rotary encoder. I may change my  
> perspective here but right now relative rotation seems more  
> interesting to me than absolute angular position. I could imagine  
> reaching different perspectives on that and going with a Hall one  
> though.

If 'chuck' does not have routines for computing derivatives and  
integrals numerically, perhaps it should have. Then it will not make  
any difference.

>> This is pretty much and individual preference - some like heavy  
>> weighted keys, and even think it helps playing faster, others the  
>> reverse. All typing keyboards seem to have an unpredictable  
>> depressing point which makes them less suitable for music  
>> interpretation.
> Well, that is what I meant; typical for the Model M is that it gives  
> both tactile and aural feedback at the exact moment the stroke is  
> registered. This makes it a favourite of some and hated in crowded  
> offices (where the noise may be objectionable).

I had one of those, but turned it back after a couple of minutes of  
use. But acoustical musical instruments do produce noise, and that is  
a part of the sound. I think that on the Roland virtual accordions,  
one can adjust the emulated sound from the keys.

> IBM went as far as outfitting some models with a actual speaker to  
> give additional noise at the moment a stroke registers, that is  
> probably taking the idea too far for most (I'm not making this up, I  
> have keyboards with a speaker grill right here though without the  
> speaker, I know it sounds far fetched).

You can implement that with 'chuck' :-). Such things were popular  
addition with Mac OS X  in the 1990s and back, but I have lost track  
of it.

>> These are the GPUs I mentioned. Mac OS X is developing special  
>> language support for these. So the exact driver thing will be  
>> transparent. Learning a new way to program fro every device  
>> requires too much of an effort. So this is probably the trend for  
>> the future.
> As a side note; this sounds revolutionary now but the Amiga platform  
> was well known for this. They used a aditional chip for sound as well.

The new thing is that the GPUs are so powerful, one can run programs  
in them. In the past, they only could do simple thing like drawing  
objects, if that. On Mac OS 9, if one wanted a window with a  
scrollbar, one had to implement a series of function calls tracing the  
events from the system. So nothing for free, there.


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