In a previous project, I needed <20 microsecond digital output response times to drive an ECU expecting a very repeatable crankshaft signal. That was a achieved using the C / PORTx trick on the forum and I ended up with a 4 microsecond resolution with an occasional 4 microsecond jitter, which worked well enough for my experiment to complete successfully.
In the interest of brevity, I have a new project in which I truly do need more speed than an Uno or Mega has available (and by speed, I mean how fast I can read and write to digital pins). I require a solid one microsecond accuracy in turning on outputs and would LIKE 1 microsecond analog reads but I understand that’s it’s own issue. If I need 1 micro, I’m shooting for hardware capable of tens of nano (10-25Mhz maybe).
I’m looking at the Due, M0 Pro, and the Edison. I don’t need many channels, just one or two in and out that I can depend on to the microsecond. Can these boards pull that off? Is there enough CPU there for maybe 20-100 lines of code to execute and not significantly influence IO timing? I was considering a Raspberry Pi using WiringPi which can achieve what I want, but I don’t really want the OS getting in the way with interrupts, etc.
Thanks for any suggestions.