Do something every trigger, jitter-free (sub-us resolution)

Projects Programming
1

Hi All,

Newbie Arduino Uno user here.

I've gone through the Timers tutorials on gammon's forum and successfully implemented the "do something every x us jitter-free" sketch, but I still can't get something to happen every trigger, jitter-free, with sub-us resolution. The closest I have come is the following sketch:

#include <util/delay.h>
#include <avr/sleep.h>

const byte interruptPin = 2;
const byte outputPin = 12;
double testDel = 10;

void trigger () {
    _delay_us(testDel);
    PORTB |= B00010000;                // pin12 high
    _delay_us(testDel);
    PORTB = B00000000;
}

void setup() {
    DDRB |= B11111111;                      // digital pins -,-,13,12,11,10,9,8 as output
    DDRD = B00000000;                       // digital pins 7,6,5,4,3,2,1,0 as input
    attachInterrupt(digitalPinToInterrupt(interruptPin),trigger,RISING);
    set_sleep_mode (SLEEP_MODE_IDLE);  
}

void loop() {
  sleep_mode ();
}

It's almost exactly what I need, but there still is some jitter, and I don't know where it could be coming from. Any ideas of where to look to reduce it?

Thanks in advance

2

...Timers tutorials on gammon's...

Your shift key appears to be wonky.

I see you also cross-posted. Please don't. Thread locked.