Hey guys,
I feel I am nearly done.
To clarify what i am trying to do again:
The aim is to create two tripwires using lasers and LDRs which work together to count the number of people entering and leaving a room. The Arduino records this number as people.
What I want to achieve is to make a constantly moving servo to adapt it's sweeping speed dependent on the number of people in the room.
Example: 0 people in the room = servo speed minimum
1 person in the room = servo speed increases
5 people in the room = servo speed increased greatly
10 people in the room = servo speed max
3 people in the room = servo speed decreased greatly
(the numbers of people would obviously not be recorded like that. It would be sequential)
This is what I am struggling with. I would use delays to easily change the servo speed but I am avoiding delays so that the whole setup operates constantly.
Does anyone have tips on how to make the servo speed change based on people number?
Thank you. 
#include <Servo.h>
const int servoMinDegrees = 0;
const int servoMaxDegrees = 180;
Servo myservo;
int servoPosition = 90; // the current angle of the servo - starting at 90.
int servoInterval = 80; // initial millisecs between servo moves
int servoDegrees = 2; // amount servo moves at each step
// will be changed to negative value for movement in the other direction
unsigned long currentMillis = 0; // stores the value of millis() in each iteration of loop
unsigned long previousServoMillis = 0; // the time when the servo was last moved
long interval = 3000;
long activatedMillis = 0;
int sensA;
int sensB;
int people = 0;
int thresh = 0;
void setup() {
Serial.begin(9600);
Serial.println("---Starting People Detection---");
pinMode(4, OUTPUT);
pinMode(2, OUTPUT);
pinMode(13, OUTPUT);
thresh = 800;
myservo.attach(9);
myservo.write(servoPosition); // sets the initial position
}
void loop(){
currentMillis = millis(); // capture the latest value of millis()
peoplecounter();
servoSweep();
sensA = analogRead(A0);
sensB= analogRead(A1);
digitalWrite(4, HIGH);
digitalWrite(2, HIGH);
people = constrain (people, 0, 10);
Serial.print("current ");
Serial.print(currentMillis);
Serial.print(" activated ");
Serial.print(activatedMillis);
Serial.print(" Servo Speed ");
Serial.print(servoDegrees);
Serial.print(" sensA is : ");
Serial.print(sensA );
Serial.print(" sensB is : ");
Serial.print(sensB );
Serial.print(" people : ");
Serial.print(people);
Serial.print(" thresh val : ");
Serial.println(thresh);
}
void peoplecounter(){
if(sensA<thresh && sensB>thresh)
{
activatedMillis = currentMillis;
people=people+1;
digitalWrite(13, HIGH);
thresh = 0;
}
else{
if(currentMillis - activatedMillis >= interval)
{thresh = 800;
}
else{
people=people;
digitalWrite(13, LOW);
}
}
if(sensA>thresh && sensB<thresh)
{
activatedMillis = currentMillis;
people=people-1;
digitalWrite(13, HIGH);
thresh = 0;
}
else{
if(currentMillis - activatedMillis >= interval)
{thresh = 800;
}
else{
people=people;
digitalWrite(13, LOW);
}
}
}
void servoSweep() {
if (currentMillis - previousServoMillis >= servoInterval) {
// its time for another move
previousServoMillis += servoInterval;
servoPosition = servoPosition + servoDegrees; // servoDegrees might be negative
if ((servoPosition >= servoMaxDegrees) || (servoPosition <= servoMinDegrees)) {
servoDegrees = - servoDegrees; // reverse direction
// and update the position to ensure it is within range
servoPosition = servoPosition + servoDegrees;
}
// make the servo move to the next position
myservo.write(servoPosition);
}
}