Vélo électrique v8

#include <Servo.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include "VescUart.h"
#include "datatypes.h"



 LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
 Servo esc;

char Str1[20];
char Str2[21];
char Str3[21];
char Str4[21];

bool etat=false;
int chrono=0;
int temps=0;
double vitesse=0;

int hallSensorPin=2;
volatile int compteur=0;
char str_vitesse[5];
char str_tension[5];
char str_courant[5];

void setup() {
  Serial.begin(115200);  // VESC
  lcd.begin(20,4);
  esc.attach(9);

  pinMode(hallSensorPin, INPUT);
  attachInterrupt(0,detectaimant,LOW);

}
struct bldcMeasure measuredValues;
void loop() {


 chrono=millis();
   if (etat == true) {
     etat=false;

     chrono = chrono - temps;
     vitesse =(2/(chrono/1000.0))*3.6;
     delay(5);
     temps=millis();

     Serial.println(vitesse);
     dtostrf(vitesse, 4, 2, str_vitesse);

   }

  sprintf(Str1, "Vitesse: %s km/h", str_vitesse);
   lcd.setCursor(0,0);
   lcd.print(Str1);

float tension = measuredValues.inpVoltage;
//dtostrf(tension, 5, 2, str_tension);
float courant = measuredValues.tempPCB;
dtostrf(courant, 5, 2, str_courant);

 sprintf(Str2, "%4d V / %4d A", tension, str_courant);
   lcd.setCursor(0,1);
   lcd.print(Str2);

  sprintf(Str3, "Throttle: %3d %", map(analogRead(A1),0,1020,0,100));
    lcd.setCursor(0,2);
    lcd.print(Str3);
}

float PWM()
{
   int PWMa = analogRead(A1);
       PWMa = map(PWM, 0, 1024, 0, 179);

   esc.write(PWMa);
}

void detectaimant()
 {
   etat= true;
 }


  /*
   * https://liudr.wordpress.com/2012/01/16/sprintf/
   * https://arduino.stackexchange.com/questions/19234/print-string-and-integer-lcd
   * https://www.electric-skateboard.builders/t/recording-data-from-vesc-summary-of-tools/7020/13
   */