Crankshaft Sensor Code

Crankshaft sensor code « on: February 09, 2013, 01:47:25 pm »

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Folks, I'm currently involved in an ev conversion project and wrote some code (well mostly copied!) to simulate a 60-2 crankshaft position sensor. Basically the sketch should output 58 pulses , skip two , another 58 and so on. A pot on A0 provides a reference for pulse width and hence rpm. Could someone please have a look at the sketch and let me know if I have the pulse counts correct as i don't have a dso to verify the output? /** crank signal simulator */ #define PULSE_PIN 10 void setup() { pinMode(PULSE_PIN, OUTPUT); } /** Simulate the high of a tooth on a reluctor wheel */ void triggerHigh(int duration) { digitalWrite(PULSE_PIN, HIGH); delayMicroseconds(duration); digitalWrite(PULSE_PIN, LOW); } /** Simulate the reference marker on a reluctor wheel */ void triggerReference(int duration) { // pin should be low already delayMicroseconds(duration); delayMicroseconds(duration); // two delays for two missing pulses. } /** Simulates a 58 tooth reluctor wheel with a 2 tooth reference */ void loop(){ int val = analogRead(0); val = map(val, 0, 1023, 100, 3500); for(int i = 0; i interval) { // 2nd cycle of LOW, LOW on pin 13 crankpin if (i == 26) { Serial.println(i); previousMillis = currentMillis; ///need some delay to keep cycles even i = 1; } } }

Here is the latest code. I have the Hz serial print working in what looks to be a correct way. My

Fluke meter says that I have frequency capability of 24Hz to 177Hz. My serial monitor shows 24 to 200. I can not run the loop faster than 200 at this point however. I need it to run up to 288Hz. I may have to use the new Fast write library that is on this forum. /* 800rpm = 13.33Hz = 75ms per RPM/26 = 2.88ms per pulse set... time between pulse state change is 1.44 ms 17,000rpm =283.33Hz = 3.529ms per RPM/26 = .1357ms per pulse set... time between pulse state change is .06787ms */ int sensorPin = A0; // select the input pin for the potentiometer int sensorValue = 0; // variable to store the value coming from the sensor unsigned long val = 0; //value to be used with map const int crankpin = 13; // the number of the LED pin //crank pulse const int campin = 12; // the number of the LED pin // cam pulse int ledState = LOW; // ledState used to set the LED int ledState2 = LOW; // ledState used to set the LED unsigned long previousMillis = 0; // will store last time LED was updated unsigned long interval = 500; // interval at which to blink (milliseconds unsigned long time = 0; unsigned long previoustime = 0; // will store last time Time was updated float Hz = 0; int i = 1; void setup() { Serial.begin(115200); // set the digital pin as output: pinMode(crankpin, OUTPUT); pinMode(campin, OUTPUT); } void loop() { sensorValue = analogRead(sensorPin); val = map(sensorValue, 0, 1023, 50, 1440); from .065ms to 1.44ms interval = val; unsigned long currentMillis = micros();

// interval adjuster

if(currentMillis - previousMillis > interval) { // 24 cycles of HIGH to LOW on pin 13 crankpin if( i < 24){ i = i++; if (i == 2){ time = (currentMillis - previoustime); Hz = (1000 / (time/1000));

Serial.println(Hz);

//print current interval

previoustime = currentMillis; } previousMillis = currentMillis; if (ledState == LOW) ledState = HIGH; else ledState = LOW; digitalWrite(crankpin, ledState); } } if(currentMillis - previousMillis > interval) { LOW, LOW on pin 13 crankpin if(i == 24 || i == 25){ pin 12 cam pin i = i++; previousMillis = currentMillis; if (ledState2 == LOW) ledState2 = HIGH; else ledState2 = LOW;

// 1st cycle of // cycle High, Low

digitalWrite(campin, ledState2); } } if(currentMillis - previousMillis > interval) { // 2nd cycle of LOW, LOW on pin 13 crankpin if (i == 26) { previousMillis = currentMillis; ///need some delay to keep cycles even i = 1; } } }

My first comment is that all your times are held as micros so the variable names are misleading. Secondly, I would expect the logic to detect when one interval has elapsed to occur once, and then use some sort of 'tooth count' to work out whether your output should be high or low. Thirdly, I'm unclear from your description whether you are trying to emulate a 'missing tooth' signal. For example a '25 -1' missing tooth signal would have three consecutive 'lows' at the missing tooth, not two. Fourthly, I suggest that whenever you have any conditional code (if, else, for, while, do etc) you always put a compound statement i.e. { and } pair, even when you only have a single statement in the conditional block. It is so easy to inadvertently tack an extra statement on, or use a macro that silently expands to more than one statement, and suddenly the logic you see

doesn't match what actually happens.

val = map(sensorValue, 0, 1023, 50, 1440); // interval adjuster from .065ms to 1.44ms As input and output range are almost equal in size you will get no nice transformation by the map function. The potmeter/ADC will fluctuate in its readings so that might give some unwanted effects. YOu can see this if you try to print interval every cycle.... refactored your code a bit /* * FILE: * AUTHOR: * DATE: * PURPOSE: * VERSION: * HISTORY: * * NOTES * * 800rpm = 13.33Hz = 75ms per RPM/26 = 2.88ms per pulse set... time between pulse state change is 1.44 ms * 17,000rpm =283.33Hz = 3.529ms per RPM/26 = .1357ms per pulse set... time between pulse state change is .06787ms * */ int sensorPin = A0; potentiometer int sensorValue = 0; from the sensor

// select the input pin for the // variable to store the value coming

unsigned long val = 0; const int crankpin = 13; pulse const int campin = 12; pulse

//value to be used with map // the number of the LED pin //crank

int ledState = LOW; int ledState2 = LOW;

// ledState used to set the LED // ledState used to set the LED

unsigned long updated unsigned long (milliseconds unsigned long unsigned long updated float Hz = 0; int i = 1;

// the number of the LED pin

// cam

previousMicros = 0;

// will store last time LED was

interval = 500;

// interval at which to blink

time = 0; previousTime = 0;

void setup() { Serial.begin(115200); // Serial.println("Start..."); // set the digital pin as output: pinMode(crankpin, OUTPUT); pinMode(campin, OUTPUT);

// will store last time Time was

} void loop() { sensorValue = analogRead(sensorPin); interval = map(sensorValue, 0, 1023, 65, 1440); adjuster from .065ms to 1.44ms

// interval

unsigned long currentMicros = micros(); time = currentMicros - previousMicros; if (time > interval) HIGH to LOW on pin 13 crankpin { previousMicros = currentMicros; i++; if (i == 2) { time = currentMicros - previousTime; previousTime = currentMicros; Hz = 1000000.0 / time; Serial.println(Hz, 2); } if (i < 24) { ledState = !ledState;

// 24 cycles of

// 2 digits

//

1 -> 0 -> 1 -> 0

etc digitalWrite(crankpin, ledState); } if (i == 24 || i == 25) { ledState2 == !ledState2; digitalWrite(campin, ledState2); } if (i == 26) { /// need some delay to keep cycles even i = 1; } } }

1) My first comment is that all your times are held as micros so the variable names are misleading. 2) Secondly, I would expect the logic to detect when one interval has elapsed to occur once, and then use some sort of 'tooth count' to work out whether your output should be high or low. 3) Thirdly, I'm unclear from your description whether you are trying to emulate a 'missing tooth' signal. For example a '25 -1' missing tooth signal would have three consecutive 'lows' at the missing tooth, not two.

4) Fourthly, I suggest that whenever you have any conditional code (if, else, for, while, do etc) you always put a compound statement i.e. { and } pair, even when you only have a single statement in the conditional block. It is so easy to inadvertently tack an extra statement on, or use a macro that silently expands to more than one statement, and suddenly the logic you see doesn't match what actually happens. Thank you for your interest and tips. PeterH. 1) Yes, I should have corrected my variable names. I started writing the program using millis() until I realized that I had to have micros(). I did not correct it after that. 2) You may be correct. 3) Yes, I am trying to emulate a 'missing tooth' signal. I thought it was '26 -2' but, I got some new information that it is '24 -2'. Based on your advice about a '25-1' wheel I think I need 5 consecutive 'lows' for my wheel at the missing tooth. Thanks for that tip. 4) I will have to look my code over more to see where the { } error is but, I will try to fix it. Quote val = map(sensorValue, 0, 1023, 50, 1440); // interval adjuster from .065ms to 1.44ms As input and output range are almost equal in size you will get no nice transformation by the map function. The potmeter/ADC will fluctuate in its readings so that might give some unwanted effects. YOu can see this if you try to print interval every cycle.... You are correct about the results of the map function that I wrote. It was not very linear and I did not like the way it was working. Also, thank you for reworking my sketch! I was struggling to solve my Hz display. I am going to try you method right away. As I said in the above post, I will have to correct the sketch from 26 cycles to 24. But that is easy enough. Thank you for you help, I will keep working at it. Here is my latest code with many improvements implemented from the suggestions given. I had to double the numbers in the "if" statements to get my '24-2' wheel result because using the shorter code that Robtillart gave me cut everything in half. I am using a Parallax USB Oscilloscope to check the pulses and the crankpin and campin timing look very good. My Hz display now works flawlessly but, the fastest my Uno can run is 106 cycles per second I am calling that Hz. I need to run at 288. My next version will have the new fastwrite library in it. /* * FILE:Crank Pulse Simulator

* AUTHOR:Mark M. with help from Robtillart * DATE:1/22/12 * PURPOSE: Simulate the output of a '24-2' crank encoder wheel and camshaft timing pin * VERSION:1 * HISTORY: * * NOTES * * 800rpm = 13.33Hz = 75ms per RPM/26 = 2.88ms per pulse set... time between pulse state change is 1.44 ms * 17,000rpm =283.33Hz = 3.529ms per RPM/26 = .1357ms per pulse set... time between pulse state change is .06787ms * */ int sensorPin = A0; potentiometer int sensorValue = 0; from the sensor

// select the input pin for the // variable to store the value coming

unsigned long val = 0; const int crankpin = 13; pulse const int campin = 12; pulse

//value to be used with map // the number of the LED pin //crank

int ledState = LOW; int ledState2 = LOW;

// ledState used to set the LED // ledState used to set the LED

unsigned long updated unsigned long (milliseconds unsigned long unsigned long updated float Hz = 0; int i = 0;

// the number of the LED pin

// cam

previousMicros = 0;

// will store last time LED was

interval = 500;

// interval at which to blink

time = 0; previousTime = 0;

// will store last time Time was

void setup() { Serial.begin(115200); Serial.println("Start..."); // set the digital pin as output: pinMode(crankpin, OUTPUT); pinMode(campin, OUTPUT); delay(1000); } void loop() { sensorValue = analogRead(sensorPin); interval = map(sensorValue, 0, 1023, 65, 1595); adjuster from .065ms to 1.44ms

// interval

unsigned long currentMicros = micros(); time = currentMicros - previousMicros; if (time > interval)

// 22 cycles of

HIGH to LOW on pin 13 crankpin { previousMicros = currentMicros; i++; if (i 0 -> 1 -> 0

//first of two cycles of

} if (i == 47) { LOW, LOW on crankpin time = currentMicros - previousTime; previousTime = currentMicros; Hz = 1000000.0 / time; Serial.println(Hz, 2);

//second of two cycles of

// 2 digits

/// need some delay to keep cycles even } if (i == 47 || i == 48) { /// need some delay to keep cycles even i = 0; } } }

Here is my next revision of my code. I increased my loop cycles per second from 106 to 120 by using the new DigitalPin.h library and commenting out the Serial.Print. DigitalPin.h library gave me a 13% speed increase which is impressive but, sadly I need 288 loop cycles per second so, I may be at the limit of the 16MHz Arduino. If anyone has a suggestions to increase my speed I am ready to hear it. I have enjoyed writing this code even though I have not reached my goal. /* * FILE:Crank Pulse3 * AUTHOR:Mark M. with help from Robtillart * DATE:1/22/12 * PURPOSE: Simulate the output of a '24-2' crank encoder wheel and camshaft timing pin * VERSION:2 * HISTORY: *Old version would run up to 106 cycles per second

*This version runs up to 120 cycles per second because faster Digital.Write and not using serail. * * NOTES * changing from standard digital.Write to DigitalPin.h methods *commented out Serial.print to maximize speed of loop * * 800rpm = 13.33Hz = 75ms per RPM/26 = 2.88ms per pulse set... time between pulse state change is 1.44 ms * 17,000rpm =283.33Hz = 3.529ms per RPM/26 = .1357ms per pulse set... time between pulse state change is .06787ms * */ #include int sensorPin = A0; potentiometer int sensorValue = 0; from the sensor

// select the input pin for the // variable to store the value coming

DigitalPin pin13; // the number of the LED pin //crank pulse DigitalPin pin12; // the number of the LED pin // cam pulse //const int crankpin = 13; // the number of the LED pin //crank pulse //const int campin = 12; // the number of the LED pin // cam pulse int ledState = LOW; int ledState2 = LOW; unsigned long was updated unsigned long (milliseconds unsigned long unsigned long updated float Hz = 0; int i = 0;

// ledState used to set the LED // ledState used to set the LED

previousMicros = 0;

// will store last time LED

interval = 500;

// interval at which to blink

time = 0; previousTime = 0;

// will store last time Time was

void setup() { Serial.begin(115200); Serial.println("Start..."); // set the digital pin as output: //pinMode(crankpin, OUTPUT); //pinMode(campin, OUTPUT); pin13.outputMode(); pin12.outputMode(); delay(1000); } void loop() { sensorValue = analogRead(sensorPin); interval = map(sensorValue, 0, 1023, 65, 1595); adjuster from .065ms to 1.44ms unsigned long currentMicros = micros();

// interval

time = currentMicros - previousMicros; if (time > interval) HIGH to LOW on pin 13 crankpin { previousMicros = currentMicros; i++; if (i 0 -> 1 -> 0

} if (i == 45 || i == 46) { LOW, LOW on crankpin ledState2 = !ledState2; if (ledState2 == LOW) { pin12.low(); } else { pin12.high(); }

//first of two cycles of

} if (i == 47) { LOW, LOW on crankpin time = currentMicros - previousTime; previousTime = currentMicros; Hz = 1000000.0 / time; //Serial.println(Hz, 2);

//second of two cycles of

// 2 digits

/// need some delay to keep cycles even } if (i == 47 || i == 48) { /// need some delay to keep cycles even i = 0; } } }

Here is a sketch I made using DigitalPin.h library and delayMicroseconds() to get my pulse interval correct. It works well except the Analog.read takes too long it seems to be 130us seconds and makes an uneven gap during the read. The map function takes about 70us.

Maybe I can somehow relocate there spot in the loop and still use them. I will have to think about it. // scope test for write timing #include // class with compile time pin number DigitalPin pin13; DigitalPin pin12; int time = 0; int sensorPin = A0; // select the input pin for the potentiometer int sensorValue = 0; // variable to store the value coming from the sensor void setup() { // set mode to OUTPUT pin13.outputMode(); pin12.outputMode(); } void loop() { sensorValue = analogRead(sensorPin); time = map(sensorValue, 0, 1023, 65, 1595); adjuster from .065ms to 1.44ms pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time);

// interval

pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); pin12.high(); delayMicroseconds(time); pin13.low(); pin12.low(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.low();

delayMicroseconds(time); }

This sketch provides even spacing but, only with 65us delays. If the delay is reduced spacing will not be equal. // scope test for write timing #include // class with compile time pin number DigitalPin pin13; DigitalPin pin12; int time = 0; int sensorPin = A0; // select the input pin for the potentiometer int sensorValue = 0; // variable to store the value coming from the sensor void setup() { // set mode to OUTPUT pin13.outputMode(); pin12.outputMode(); } void loop() { pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time);

pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); delayMicroseconds(time); pin13.low(); delayMicroseconds(time); pin13.high(); pin12.high(); delayMicroseconds(time); pin13.low(); pin12.low(); delayMicroseconds(time); pin13.low(); sensorValue = analogRead(sensorPin); //delayMicroseconds(time - 65); pin13.low();

//delayMicroseconds(time - 65); pin13.low(); time = map(sensorValue, 0, 1023, 65, 1595); adjuster from .065ms to 1.44ms //delayMicroseconds(time - 65); pin13.low(); delayMicroseconds(time);

// interval

}

/* 60-2 tooth CAS signal generator for bench testing Bosch Motronic ECUs. Connect a linear 10k potentiometer's pin 1 to VCC, pin 2 to A0, pin 3 to GND. TTL CAS signal output is on pin 12. */ int PotPin = A0; potentiometer int PotValue = 0; coming from the sensor int CASpin = 12; int LEDpin = 13;

// the input pin for the // variable to store the value // CAS out pin // on-board LED

void setup() { pinMode(CASpin, OUTPUT); pinMode(LEDpin, OUTPUT); } void loop() { PotValue = analogRead(PotPin); // read the value from the potentiometer digitalWrite(LEDpin,LOW); int PulseDelay = 50000 / PotValue; // 50000 gives >7000 rpm which is enough if (PotValue > 5) // Stop signal output at minimum pot value { digitalWrite(LEDpin,HIGH); // LED indicates CAS signal status for (int j = 0; j < 5; j++) // Update the RPM only every few revolutions { for (int i = 0; i < 58; i++) // 58 of the 60 teeth high/pause/low/pause cycle { digitalWrite(CASpin, HIGH); delayMicroseconds(PulseDelay); digitalWrite(CASpin, LOW); delayMicroseconds(PulseDelay); } for (int i = 0; i < 4; i++) // 2 missing teeth are low for both halves of cycle { delayMicroseconds(PulseDelay); } } }

}

EDIT: sólo soy capaz de llegar a 120 Hz o 7.200 rpm con un boceto que es un poco mejor que éste. Necesito un chip más rápido.

En mi post anterior me pareció que la rueda del cigüeñal tenía 24 dientes y 2 zonas sin cubrir, pero ahora me doy cuenta de que es de 22 dientes con 2 áreas descubiertas = 24 así decirlo. Tengo un código para generar los pulsos y reporte el Hz de rpms. La Hz es ajustable con un bote. Estoy mostrando un extremo inferior de 1280rpm hasta ahora. En el momento que estoy limitado a alrededor de 120 Hz o 7.200 rpm. Mi Hz impresión no funciona correctamente al 100% todavía. Yo lo la impresión tiene un problema de redondeo en los cálculos. Aquí está el código si alguien puede leerlo.

[code]/* ///this math needs work 800rpm = 13.33Hz = .075ms per RPM/24 = 3.1ms per pulse set... time between pulse state change is 1.56 ms 17,000rpm =283.33Hz = 3.529ms per RPM/24 = .147ms per pulse set... time between pulse state change is .0735ms */ int sensorPin = A0; // select the input pin for the potentiometer int sensorValue = 0; // variable to store the value coming from the sensor unsigned long val = 0; //value to be used with map const int crankpin = 13; // the number of the LED pin //crank pulse const int campin = 12; // the number of the LED pin // cam pulse int ledState = LOW; // ledState used to set the LED int ledState2 = LOW; // ledState used to set the LED unsigned long previousMillis = 0; // will store last time LED was updated unsigned long interval = 500; // interval at which to blink (milliseconds unsigned long time = 0; unsigned long previoustime = 0; // will store last time Time was updated float rpm = 0; int i = 1; void setup() { Serial.begin(115200); // set the digital pin as output: pinMode(crankpin, OUTPUT); pinMode(campin, OUTPUT); } void loop() { sensorValue = analogRead(sensorPin); val = map(sensorValue, 0, 1023, 50, 1440); interval = val; unsigned long currentMillis = micros();

// interval adjuster from .065ms to 1.44ms

if(currentMillis - previousMillis > interval) { // 24 cycles of HIGH to LOW on pin 13 crankpin if( i < 22){ i = i++; if (i == 2){ time = (currentMillis - previoustime); rpm = (1000 / (time/1000)); Serial.println(rpm * 60); //print current interval previoustime = currentMillis;

} previousMillis = currentMillis; if (ledState == LOW) ledState = HIGH; else ledState = LOW; digitalWrite(crankpin, ledState); }

}

if(currentMillis - previousMillis > interval) { // 1st cycle of LOW, LOW on pin 13 crankpin if(i == 22 || i == 23){ // cycle High, Low pin 12 cam pin i = i++; previousMillis = currentMillis; if (ledState2 == LOW) ledState2 = HIGH; else ledState2 = LOW; digitalWrite(campin, ledState2); } } if(currentMillis - previousMillis > interval) { // 2nd cycle of LOW, LOW on pin 13 crankpin if (i == 24) { previousMillis = currentMillis; ///need some delay to keep cycles even i = 1; } } }

/** crank signal simulator */ #define PULSE_PIN 10

void setup() { pinMode(PULSE_PIN, OUTPUT); } /** Simulate the high of a tooth on a reluctor wheel */ void triggerHigh(int duration) { digitalWrite(PULSE_PIN, HIGH); delayMicroseconds(duration); digitalWrite(PULSE_PIN, LOW); } /** Simulate the reference marker on a reluctor wheel */ void triggerReference(int duration) { // pin should be low already delayMicroseconds(duration); delayMicroseconds(duration); // two delays for two missing pulses. }

/** Simulates a 58 tooth reluctor wheel with a 2 tooth reference */ void loop(){ int val = analogRead(0); val = map(val, 0, 1023, 100, 3500);

for(int i = 0; i