Re: Help with embedded hardware/software platform selection for ADA

[mjsilva@scriptoriumdesigns.com]

On Tuesday, July 2, 2013 10:27:08 AM UTC-7, Dmitry A. Kazakov wrote:
 
> ...Otherwise there is no problem to have a 100us control loop under a "normal"
> 
> OS like Linux or VxWorks. Even under Windows you can have stable 5ms
> 
> (Windows has timer resolution issues, performance is basically OK).
> 
I'm still trying to convey that what both Simon and I are talking about are boards 10-100 times less expensive than ones that can run those OSes, using micros that cost as little as a dollar or two.  The fat part of the pyramid, as I said earlier.  Here are two examples off the top of my head (both found in many commercial products, not just hobby projects):

(a) Electronic speed controls (ESCs).  They drive brushless DC motors at many thousands of RPM, adjusting the 3-phase PWM and reading back-EMF during coasting periods.  Rather average specs would be a 50us PWM window, including an ADC read, all using a micro that costs well under $1.

(b) RGB LED control.  Controllable RGB LEDs require data at a rate of 800kbps over a single clock/data line, daisy chained up to 1000 LEDs per controller.  Again, using a micro in the 1-2 dollar range.

I could add to this list of examples indefinitely, without coming anywhere near your Windows/Linux/VxWorks world.