// FSR output controls speed of stepper motor

int minimum = 1023, maximum = 0; // determine min and max FSR value

int dirPin = 11, stepPin = 12, fsrPin = A0, fsrValue;
int fsrMin = 0, fsrMax = 1023; // replace with measured values
int waitMin = 2, waitMax = 100; // milliseconds
unsigned long timer, timeout;

void setup() {
  Serial.begin(115200);
  pinMode(dirPin, OUTPUT);
  pinMode(stepPin, OUTPUT);
  digitalWrite(dirPin, HIGH); // CW direction
}

void loop() {
  findMinMax(); // find minimum and maximum of Force Sensitive Resistor
  // readSensor(); // control Stepper Motor with FSR
}

void readSensor() {
  fsrValue = analogRead(fsrPin);
  timeout = map(fsrValue, fsrMin, fsrMax, waitMax, waitMin); // no force = max wait, max force = min wait
  if (timeout < 100) { // stop motor if FSR does not sense force
    if (millis() - timer > timeout) { // if timeout is exceeded
      timer = millis(); // reset timer
      stepMotor(); // motor one step
    }
  }
}

void stepMotor() {
  digitalWrite(stepPin, HIGH);
  delayMicroseconds(2000);
  digitalWrite(stepPin, LOW);
  delayMicroseconds(2000);
}

void findMinMax() {
  int fsr = analogRead(A0);
  if (fsr < minimum)
    minimum = fsr;
  if (fsr > maximum)
    maximum = fsr;
  Serial.print("min ");
  Serial.print(minimum);
  Serial.print(" (reading ");
  Serial.print(analogRead(A0));
  Serial.print(") max ");
  Serial.println(maximum);
  delay(100);
}