How long to wait? or Estimating millis() or micros() that each loop takes

Projects Programming
1

Is there a way to estimate (or measure) how long each section of a larger program takes to run through so that I can program millis() delays correctly?

Is my r3 UNO fast enough that I should be using micros() instead even if I'm measuring at 100 or even 250 microsecs a pass?

I've got two sensors, two pots controlling a servo each, and two LED arrays (one responds to time, the other from inputs from both sensors, code for either has been omitted from the sample below). I'm still trying to build the hardware side, but I'm already thinking software side. I'm wanting to know how long to set my tokens before expiring them to allow the sensors to be read again, the pots to be consulted then if necessary update the servos, and the LEDs to be adjusted.

Below is the working prototype of the structure I'm working on, advise on this as well is gratefully accepted.

Sample PseudoCode:

void loop();

int LONG heartbeat;
heartbeat = milis();
if (SensorA) { // A photocell
  See if the token set from the last time the sensor was measured has expired
    if (TokenExpired) { 
       Its been long enough, do something
       Set Token for [x] millis()
    }  else {
       Its not been long enough
       Token--
    }
}

if (SensorB) { // An electret mic
  See if the token set from the last time the sensor was measured has expired
    if (TokenExpired) { 
       Its been long enough, do something
       Set Token for [x] millis()
    }  else {
       Its not been long enough
       Token--
    }
}

if (PotA) { // controls ServoA
  See if the token set from the last time the pot was measured has expired
    if (TokenExpired) { 
       Its been long enough
         if (PotA has a different value) {
           move servoA to new value
           Set Token for [x] millis()
         }
    }  else {
       Its not been long enough
       Token--
    }
}

if (PotB) { // controls ServoB
  See when PotB was last checked
    if (TokenExpired) { 
       Its been long enough
         if (PotB has a different value) {
           move servoB to new value
           Set Token for [x] millis()
         }
    }  else {
       Its not been long enough
       Token--
    }
}
2

There is no need to calculate the number of iterations in a busy loop when you can measure time directly:

    static unsigned long lastPotAReadTime = 0;
    unsigned long currentTime = millis();
    if (currentTime - lastPotAReadTime > 100)  // Has it been more than 100 milliseconds since we last checked?
        { 
        // Its been long enough
        sevoA.write(analogRead(PotA) * 180 / 1023);   // move servoA to new value
        lastPotAReadTime = currentTime;
         }