ESP8266 seems to be killing a while loop

Question

When i was testing out a program I found a strange behavior of esp8266

It seems to get out of a while loop even when there's no option of getting out on code

I don't know if these are related but here's the code (the program is just two different visual patterns of leds toggled by a button)

#define led1 D0
#define led2 D1
#define led3 D2
#define led4 D3
#define button D7

unsigned long pressedButton;
bool change = 0;
unsigned long previousTime;
unsigned int difference;


void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(button, INPUT_PULLUP);
}

void loop(){
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);         //when the while loop change, this should delete interference
  digitalWrite(led4, LOW);
  previousTime = millis();
  
  while (!change){                                      //default visual pattern of leds
    difference = millis()-previousTime;
    
    if (!digitalRead(led1) && difference>=200){
      digitalWrite(led1, HIGH);
    }
    if (!digitalRead(led2) && difference>=400){
      digitalWrite(led2, HIGH);
    }
    if (!digitalRead(led3) && difference>=600){
      digitalWrite(led3, HIGH);
    }
    if (!digitalRead(led4) && difference>=800){         //after here, all the leds should be HIGH
      digitalWrite(led4, HIGH);
    }
    if (digitalRead(led4) && difference>=1000){
      digitalWrite(led4, LOW);
    }
    if (digitalRead(led3) && difference>=1200){
      digitalWrite(led3, LOW);
    }
    if (digitalRead(led2) && difference>=1400){
      digitalWrite(led2, LOW);
    }
    if (digitalRead(led1) && difference>=1600){        //after here, all the leds should be LOW
      digitalWrite(led1, LOW);
      previousTime = millis();
    }
    
    if (!digitalRead(button) && millis()-pressedButton>200){       //check if button was pressed to break while loop
      pressedButton = millis();
      break;
    }
  }

  
  while (change){                                         //alternative of visual pattern of leds
    difference = millis()-previousTime;
    
    if (!digitalRead(led1) && difference>=200){
      digitalWrite(led1, HIGH);
      digitalWrite(led4, HIGH);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
    }
    if (digitalRead(led1) && difference>=400){
      digitalWrite(led1, LOW);
      digitalWrite(led4, LOW);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, HIGH);
      previousTime = millis();
    }

    //if (!digitalRead(button) && millis()-pressedButton>=200){     //check if button was pressed to break while loop
    //  pressedButton = millis();
    //  break;
    //}
  }
  
  change = !change;         //after a break in one of the while loops, this will make the program go to the other while loop
 }

Is there something wrong with the code? Here is a link of a video of the behavior for more details https://drive.google.com/file/d/1822MHNGQn-A2-HGHhRXz_8xydz-wM4Ha/view?usp=sharing

Answer 1

You can't trap an ESP in a while loop like that. There are things it needs to get back to main and do between loops. Instead, let the loop function be your loop. Make the while statements if statements and where you have break, that's where you change the change variable. Put the code at the top in an if statement that checks to see if change has changed.

#define led1 D0
#define led2 D1
#define led3 D2
#define led4 D3
#define button D7

unsigned long pressedButton;
bool change = 0;
bool oldChange = 1;
unsigned long previousTime;
unsigned int difference;


void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(button, INPUT_PULLUP);
}

void loop() {
  if (change != oldChange) {
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);  //when the while loop change, this should delete interference
    digitalWrite(led4, LOW);
    previousTime = millis();
    oldChange = change;
  }

  if (!change) {  //default visual pattern of leds
    difference = millis() - previousTime;

    if (!digitalRead(led1) && difference >= 200) {
      digitalWrite(led1, HIGH);
    }
    if (!digitalRead(led2) && difference >= 400) {
      digitalWrite(led2, HIGH);
    }
    if (!digitalRead(led3) && difference >= 600) {
      digitalWrite(led3, HIGH);
    }
    if (!digitalRead(led4) && difference >= 800) {  //after here, all the leds should be HIGH
      digitalWrite(led4, HIGH);
    }
    if (digitalRead(led4) && difference >= 1000) {
      digitalWrite(led4, LOW);
    }
    if (digitalRead(led3) && difference >= 1200) {
      digitalWrite(led3, LOW);
    }
    if (digitalRead(led2) && difference >= 1400) {
      digitalWrite(led2, LOW);
    }
    if (digitalRead(led1) && difference >= 1600) {  //after here, all the leds should be LOW
      digitalWrite(led1, LOW);
      previousTime = millis();
    }

    if (!digitalRead(button) && millis() - pressedButton > 200) {  //check if button was pressed to break while loop
      pressedButton = millis();
      change = true;
    }
  }


  if (change) {  //alternative of visual pattern of leds
    difference = millis() - previousTime;

    if (!digitalRead(led1) && difference >= 200) {
      digitalWrite(led1, HIGH);
      digitalWrite(led4, HIGH);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
    }
    if (digitalRead(led1) && difference >= 400) {
      digitalWrite(led1, LOW);
      digitalWrite(led4, LOW);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, HIGH);
      previousTime = millis();
    }
  }

  change = false  
}