Boolean variable in a while loop (Smart Garden)

[lorenzoscavarda]

Hi to everybody,

I'm working on a smart garden project with an Arduino MkR wifi 1010 and MkR IoT Carrier. In my project I have one water pump connected to a Relay and nothing else. Thanks to the arduino cloud I can manage the pump by mean a boolean variable. In particular I can change its value trough the Dashboard of the cloud (I attach screenshot below).
Everything works well but I would like to improve my code. In the specific I would like to keep opened the Relay (and so give water to the plant) only for a fixed time (that I choose at the beginning of the code). So in a function I have put a "while" loop in order to give water until two conditions are verified: 1) if the boolean variable connected to pump is true 2) if the time is less than the timer set. However, I would like that if I change the value of boolean variable to False before that timer is expired the pump stops. But I can't do it. I don't know why but if the code enters in the while loop, it doesn't exit if I change the waterpump status to false. It is like it doesn't update the variable. I attach also the full code. Someone can help me?
Thanks a lot in advance,
Cheers,
Lorenzo

#include "thingProperties.h"
#include <Arduino_MKRIoTCarrier.h>
MKRIoTCarrier carrier;

int moistPin = A5;
int dry = 1023;
int wet = 0;
unsigned long timer = 100000; //ms

String lightState;
String waterPumpState;

uint32_t lightsOn = carrier.leds.Color(82, 118, 115);
uint32_t lightsOff = carrier.leds.Color(0, 0, 0);

void setup() {
  // Initialize serial and wait for port to open:
  Serial.begin(9600);
  //enable only if you work with the pc
  //while (!Serial);
 
  // Defined in thingProperties.h
  initProperties();
 
  // Connect to Arduino IoT Cloud
  ArduinoCloud.begin(ArduinoIoTPreferredConnection);
  //Get Cloud Info/errors , 0 (only errors) up to 4
  setDebugMessageLevel(2);
  ArduinoCloud.printDebugInfo();
 
  //Wait to get cloud connection to init the carrier
  while (ArduinoCloud.connected() != 1) {
    ArduinoCloud.update();
    delay(500);
  }
 
  CARRIER_CASE = true;
  carrier.begin();
  carrier.display.setRotation(0);
  delay(1500);
}

void loop() {
  ArduinoCloud.update();

  //read temperature and humidity
  temperature = carrier.Env.readTemperature();
  humidity = carrier.Env.readHumidity();
  
  //print for debugging
  //Serial.print("T: ");
  //Serial.println(temperature);
  
  //Update touch buttons
  carrier.Buttons.update();
  	
  //function to print out values
  if (carrier.Buttons.onTouchDown(TOUCH0)) {
    printInfo();
  }
  
  if (carrier.Buttons.onTouchDown(TOUCH1)) {
    printInfoRelays();
  }
  
  //read raw moisture value
  int raw_moisture = analogRead(moistPin);

  //map raw moisture to a scale of 0 - 100
  moisture = map(raw_moisture, wet, dry, 100, 0);
  
  //read ambient light
  while (!carrier.Light.colorAvailable()) {
    delay(5);
  }
  int none;
  carrier.Light.readColor(none, none, none, light);
  
  delay(100);
}

void onWaterpumpChange() {
  
  unsigned long dt=0;
  while ((waterpump == true) && (dt <= timer)){
    carrier.Relay2.open();
    waterPumpState = "PUMP: ON";
    updateScreen();
    //set timer [ms] to turn OFF the pump
    delay(1000);
    dt=dt+1000; 
  }
  waterpump = false;
  carrier.Relay2.close();
  waterPumpState = "PUMP: OFF";
  updateScreen();
}

void onArtificialLightChange() {
  if (artificial_light == true) {
    carrier.leds.fill(lightsOn, 0, 5);
    carrier.leds.show();
    lightState = "LIGHTS: ON";
  } else {
    carrier.leds.fill(lightsOff, 0, 5);
    carrier.leds.show();
    lightState = "LIGHTS: OFF";
  }
  updateScreen();
}

//Update displayed Info
void printInfo(){
  carrier.display.fillScreen(ST77XX_BLACK);
  carrier.display.setTextColor(ST77XX_WHITE);
  carrier.display.setTextSize(2);
 
  carrier.display.setCursor(40, 60);
  carrier.display.print("Water: ");
  carrier.display.print(moisture);
  carrier.display.println("%");
  
  carrier.display.setCursor(40, 80);
  carrier.display.print("T: ");
  carrier.display.print(temperature);
  carrier.display.println("C");
  
  carrier.display.setCursor(40, 100);
  carrier.display.print("Hum: ");
  carrier.display.print(humidity);
  carrier.display.println("%");
}

void printInfoRelays(){
  carrier.display.fillScreen(ST77XX_BLACK);
  carrier.display.setTextColor(ST77XX_WHITE);
  
  carrier.display.setTextSize(3);
  carrier.display.setCursor(40, 50);
  carrier.display.print(waterPumpState);
  carrier.display.setCursor(40, 90);
  carrier.display.print(lightState);
}

//Update carrier screen
void updateScreen(){
  printInfoRelays();
}```

[UKHeliBob]

  while ((waterpump == true) && (dt <= timer))
  {
    carrier.Relay2.open();
    waterPumpState = "PUMP: ON";
    updateScreen();
    //set timer [ms] to turn OFF the pump
    delay(1000);
    dt = dt + 1000;
  }

What is going to change the state of the waterpump variable in the while loop ?

[MarkT]

Don't use a while loop - you simply hang everything off loop(), so that everything can progress as needed.

Think of the program as having states, and store the state in a variable. One state is the pump has been triggered, but hasn't yet timed-out.
Another is the pump has been triggered, timed out and is now off.
Another is the pump has been cancelled.

Various events and time-outs drive the changes to the current state, and these changes perform relevant actions.

This is how event-driven programming using state-machines works, and is what microcontrollers typically do.

Your events are the boolean variable changing, and the timeout completing.
Your actions are controlling the pump and starting/cancelling the timer.

Google "state transition diagram".

[lorenzoscavarda]

I thought to attach a picture, but probably I forgot it. In the Dashboard you can read or write some variables. In this case I can change the value of the waterpump.

[UKHeliBob]

@lorenzoscavarda

I can change the value of the waterpump

Will the value change when the code is actually in the while loop ?

[lorenzoscavarda]

Thanks for you answer. If I understood well, you are saying to remove the function "void onWaterpumpChange()" and write the content in the loop() function, right? Anyway inside the loop I need in any case another "loop" (as a "while" or "for"), because I need that the waterpump stay opened for fixed time. In other case it's not very clear to me with what replace the "while" loop.
So, I should write something like:

void loop() {
  ArduinoCloud.update();

  //read temperature and humidity
  temperature = carrier.Env.readTemperature();
  humidity = carrier.Env.readHumidity();
  if (waterpump == True){
      while(dt <= timer){
           [....]
       }
  }

[lorenzoscavarda]

I hoped yes. But practically not. When I open the waterpump, the code enters in the loop and stay there up to the timer is expired. But if before that I try to set again the waterpump to false (from the dashboard), the code doesn't understand and it remains in the while loop. For me that is a problem, because if for example I turn on the pump by mistake I would like to stop it immediataly from the Dashboard and not wait the ending of the timer.

[UKHeliBob]

Change the while loop to an if and let loop() do the looping. That way the code will not be blocked and will be able to respond to external inputs

[lorenzoscavarda]

Thanks a lot. I will try and I will let you know.

Cheers,
Lorenzo

[lorenzoscavarda]

Thanks a lot. I solved my problem!

[UKHeliBob]

I am glad that you got it working

Please post your revised code to help anyone with a similar question in the future