Reading values with HC-05 and sending commands at the same time working inconsistently

Question

Not good at coding at all, so I'm at a total loss here.

But I'm doing a project that involves controlling a larger DC voltage through a mosfet. What I'm doing is I'm using a HC-05 to transmit data between a phone and the Arduino Uno. Seeing the value within a couple of seconds is necessary.

However, sending the mosfet gate a command to open or close up work very inconsistently. Sometimes never and sometimes it takes up to 30 seconds for it to register.

The code here is a short version of the project that I'm working on, but behaves similarly.

#define mosfet 11
int state = 0;          
int gate = 0;
int maxgate = 255;      
int mingate = 0;        

void setup() {
  delay(2000);
  pinMode(mosfet, gate);
  analogWrite(mosfet, 0);   //starts closed
  Serial.begin(9600); 
}

void loop() {
  while(Serial.available() > 0){
    state = Serial.read();

    for (int y=0; y <= 5; y+=5){
      delay(500);
      Serial.println("testphase 1");
      delay(500);
    }

    for (int y=5; y >= 0; y--){
      delay(250);
      Serial.println("testphase 2");
      delay(250);
    }

    if (state == '0') {                   
    gate = gate + 1;
    if(gate > maxgate) gate = maxgate;
    analogWrite(mosfet, gate);                        
    Serial.println(int(gate));Serial.print(", +1"); 
    state = 0;
    }

  if (state == '1') {                                   
    gate = gate + 10;
    if(gate > maxgate) gate = maxgate;
    analogWrite(mosfet, gate);                          
    Serial.println(int(gate));Serial.print(", +10");    
    state = 0;
    }
} 
}  

When sending 'State == 1', for example it will go through both for loops multiple times and the maybe sometimes do gate + 10. Sometimes the commands goes completely ignored.

I have no idea how I would interrupt a loop to execute the given command and then go back.

Answer 1

Actually got it working myself, but thank you so much for your help @chrisl

Ditched the for loop completely just to try things out and reorganized my code a bit. Surprisingly it started to work well enough.

Basically just moved my measuring stuff outside the while loop*(and now that I think about it, why would it ever be withing the while loop? Literally makes no sense)* and to the end of the whole void loop part, and only polled for state changes within the while loop while the BT connection was active.

Doesn't miss a command as far as I can tell, and the adjustment is within 2 seconds when using my whole code, which is perfect. Also the whole program doesn't just freeze itself while trying to think what happened when the change set was send.

Here's a short version, should somebody bump into this thread in the future.

void loop() {
   while(Serial.available() > 0){       
    state = Serial.read();              

  if (state == '0') {stuff happens here,
    }
    }  //End of the while loop.

  sensors.requestTemperatures();
  delay(1000); 
  Celcius=sensors.getTempCByIndex(0);
}