Arduino Starter sketch for Tach

sketch_tach_starter.ino

// Read and process hall effect sensor for use as tach
// See https://www.allelcoelec.com/blog/A3144-Hall-Effect-Sensor-Pinout,Alternatives,and-Applications.html for hookup

#define HALL_EFFECT_PIN 2

int sensor_value = 0 ;    // output from hall sensor, low for detect

void setup() {
  // put your setup code here, to run once
  Serial.begin( 115200 ) ;
  pinMode( HALL_EFFECT_PIN, INPUT) ;
}

// See: https://sepwww.stanford.edu/sep/prof/pvi/zp/paper_html/node2.html#_prog:copy for theory
float leakyIntegrator( int new_sample, float rho )
{
  // Type your code for the leaky integrator here -- see image in slides
  float output_value = 0.0 ;
 
  return output_value ;
}
// Utility routine to hack the automatic scaling off for the plot
void plotSpeed (float max_value, float sensorValue)
{
  Serial.print(0); // To freeze the lower limit
  Serial.print(" ");
  Serial.print(max_value); // To freeze the upper limit
  Serial.print(" ");
  Serial.println(sensorValue); // To send all three 'data' points to the plotter
}

// loop reading sensor and processing each 1/10 second
void loop() {
  sensor_value = digitalRead( HALL_EFFECT_PIN ) ;
  sensor_value = !sensor_value ;                          // flip value of sensor output to get a 1 when triggered
  float result = leakyIntegrator( sensor_value, 0.85) ;  // integrate. rho must be float value <1.0
  plotSpeed( 10, result) ;                                // show the plot
  delay ( 100 ) ;
}