OK... tracked down the problem.
Was in some old code... the most basic function "fastDigitalWrite" had the SET/CLEAR values transposed... so basically set was unsetting and unset was setting.
I tested that function using leds and "blink".... which made it hard to test that HIGH->ON and LOW->OFF.
Ended up making a SoftSPI class I could drop into my main classes. It ended up worse than the SPI lib cause fastDigitalWrite is used for everything.
I'd almost guess the SPI with FIFO and from standard lib will work when I put them back in.
glitches aside, the lower clocked Teensy 3.1 @72Mhz is giving the Due benchmarks a good workout.
Was in some old code... the most basic function "fastDigitalWrite" had the SET/CLEAR values transposed... so basically set was unsetting and unset was setting.
I tested that function using leds and "blink".... which made it hard to test that HIGH->ON and LOW->OFF.
Ended up making a SoftSPI class I could drop into my main classes. It ended up worse than the SPI lib cause fastDigitalWrite is used for everything.
I'd almost guess the SPI with FIFO and from standard lib will work when I put them back in.
glitches aside, the lower clocked Teensy 3.1 @72Mhz is giving the Due benchmarks a good workout.