2022-11-10 (Th) PoweredInlineSkatesRev2 Checking pulse width with interrupts

Interrupts are a feature where a program will stop whatever it is doing if a hardware pin goes to a designated state. In this example, I want to check the time the instant a motor pulse rises and again when it falls. I had never learned interrupts, and this seemed like a perfect time to teach myself. The results were similar to yesterday's, but some differences are worth noting. Measuring a steady signal with pulseIn() spanned 14 microseconds but interrupts showed a span of 24 microseconds. The Arduino Micro's processor has a 16MHz clock speed, so it should have had a resolution of 2 microseconds, but with interrupts, it appeared to be 4, and with pulseIn(), it seemed like it was 1.

A motor timing pulse is 1,000 to 2,000 microseconds, so erratic behavior in the range of 14 or 24 microseconds is 1.4% and 2.4%, respectively. I don't have the experience to know that an ESC won't respond poorly to these differences.
Side-by-side comparison of measurements

I am not confident in my code for generating the timing pulses, so I got a servo expansion board connecting up to 16 motors with a chip designed to generate modulated pulses. I had to circumvent the typical wiring to power everything from USB without adding wire splitters. I will test this signal's quality against the ones I've been generating.
Servo control board

The rest of the posts for this project have been arranged by date.
First time here?

Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5
Completed projects from year 6
Completed projects from year 7
Completed projects from year 8

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