Re: [rtl] generate squares

[Thomas Eschenbacher <Thomas.Eschenbacher@gmx.de>]

Paolo Mantegazza wrote:
> [...]
> >     I want to generate squares from parallel in the highest frequency and
> > stable needed. pthread_create() and pthread_make_periodic_np() only give me
> > the stable square wave about 30k HZ. I need 120k HZ or more.
> 
> Forget about that. On whatever PC, with whatever real time OS, you'll
> have jitters greater than the period you want. So while you can use that
> rate without jamming your machine the square wave seen on a memory scope
> will be just a thick black strip. Hand on experience.

...just an idea: maybe you can make use of the PC's built-in hardware.
For example it is possible to generate squares out of the serial port by
programming a baudrate and transmitting a bit pattern. So you can
produce up to 115,2 kHz with standard hardware. But I have heard of some
new UARTs that can do higher rates. Maybe you can also "misuse"
something like an IRDA transmitter for that.

bye,
   Thomas
-- 
________________________________________________________________________
Thomas Eschenbacher                           Thomas.Eschenbacher@gmx.de