Determine RPM of DC Motor using Encoder

Other Hardware Motors, Mechanics, Power and CNC
4

This code is extracted from a program I use to control a small DC motor. I have an optical sensor that produces one pulse per revolution. It is not complete but it should give the idea. It simply measures the time between pulses.

volatile unsigned long isrMicros;
unsigned long latestIsrMicros;
unsigned long previousIsrMicros;
volatile boolean newISR = false;


void loop() {
   if (newISR == true) {
     previousIsrMicros = latestIsrMicros; // save the old value
     noInterrupts(); // pause interrupts while we get the new value
        latestIsrMicros = isrMicros;
        newISR = false;
     interrupts();
     microsThisRev = latestIsrMicros - previousIsrMicos;
}

void myISR() {
   isrMicros = micros();
   newISR = true;
}

...R