Button and millis little problem

Projects Programming
1

Hello my friend. I write my sketch for my car and i have a problem to read state my button. Sketch i write with millis() and this is problem because i don't understand 100% millis(); Can somebody help me i copy here little my sketch.

int ThermistorPin1 = A0;
int ThermistorPin2 = A1;
int Vo;
float R1 = 10000;
float logR2, R2, T, Temp_water, Temp_exhaust;
float c1 = 1.009249522e-03, c2 = 2.378405444e-04, c3 = 2.019202697e-07;

int fan_pin = 3;
int glow_plug_pin = 5;
int fuel_pump_pin = 6;
int push_pin = 13;

float fuel_need;
float glow_time;
float fan_speed;

void setup() {
  Serial.begin(9600);
  pinMode(fan_pin, OUTPUT);
  pinMode(glow_plug_pin, OUTPUT);
  pinMode(fuel_pump_pin, OUTPUT);
  pinMode(glow_plug_pin, HIGH);
  pinMode(fuel_pump_pin, HIGH);



  pinMode(push_pin, INPUT_PULLUP);
  pinMode(A0, INPUT);
  pinMode(A5, INPUT);
}

void loop() {
  webasto_control();
  temp_control();

  fuel_pump();
  fan();
  glow_plug();
}



void webasto_control() {
  static unsigned long timer;
  if (millis() < timer) {
    timer = millis();
  }

int reading = digitalRead(push_pin);

if(reading == LOW){
   if (millis() > timer + 500) {
    fuel_need = 0;                    // Here I need: when state button is LOW and Temp_exhaust > 20 do:
    fan_speed = 100;                   fuel_need = 0;   fan_speed = 100;    glow_time = 0;
    glow_time = 0;
  }
}
if(reading == HIGH){
  fuel_need = 0;                   // Here i need when state button is HIGH start my program.
    fan_speed = 0;
    glow_time = 0;
}


  if (millis() > timer + 500) {
    fuel_need = 0;
    fan_speed = 100;
    glow_time = 0;
  }
  if (millis() > timer + 3500) {        
    fuel_need = 0;
    fan_speed = 0;
    glow_time = 0;

  if (millis() > timer + 30000 && Temp_water > 0 && Temp_exhaust > 45) {
    glow_time = 0;
    fuel_need = 90;
    fan_speed = 70;
  }


  if (millis() > timer + 45000 && Temp_exhaust < 25) {
    glow_time = 0;
    fuel_need = 0;
    fan_speed = 0;
  }
2

Welcome to the forum. +1 karma for using code tags. -1 karma for not explaining what problem you are having. What did you want the code to do? What does it do?

3

Also you did not post a complete sketch.

4

The demo Several Things at a Time illustrates the use of millis() to manage timing without blocking. It may help with understanding the technique.

Have a look at Using millis() for timing. A beginners guide if you need more explanation.

...R