Running a timer code which gets stuck at zero - c++

Question

OK so firstly, I am VERY new to C++ as you will undoubtedly see from the code. I have been struggling with this to get it to where it is now so my apologies if it's not very good.
Ok here is what SHOULD happen.
Button 2 (downButton) is pressed to select the correct program (that works).
Button 3 (startButton) is used to start the timer for that program (that works)
The timer is supposed to count down (also working) and when it reaches zero, display a message and then go back to the start of the switch case.
This is what I am struggling with. Firstly the timer gets to zero and does nothing else. I have tried return, goto etc without any success.
I commented out the end message function, which does work BUT still gets stuck there without exiting the function.
What I am looking for is a little help to make the timer jump back to where it was called from.
Here is the code:
#include <Wire.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int hours = 0; // start hours
int minutes = 00; //start min
int seconds = 05; //start seconds
const int buttonPin = 9; // the pin that the pushbutton is attached to
const int ledPin = A0; // the pin that the LED is attached to
const int ledPin2 = A1; // the pin that the LED is attached to
int buttonState = 0; // current state of the button
int WhichScreen = 0; // This variable stores the current Screen number
boolean hasChanged = true;
const int upButton = 8; // the number of the select pin
const int downButton = 10; // the number of the select pin
const int startButton = 9; // the number of the start pin
int selectState; // the current reading from the select pin
int lastSelectState = LOW; // the previous reading from the select pin
int backState; // the current reading from the select pin
int lastBackState = LOW; // the previous reading from the select pin
int startState; // the current reading from the start pin
int lastStartState = LOW; // the previous reading from the start pin
unsigned long lastDebounceTime = 0; // the last time the output pin was toggled
unsigned long debounceDelay = 50; // the debounce time; increase if the output flickers
void setup()
{
Serial.begin(9600);
pinMode(buttonPin, INPUT); // initialize the button pin as a input
pinMode(ledPin, OUTPUT); // initialize the button pin as a output
pinMode(ledPin2, OUTPUT); // initialize the button pin as a output
lcd.begin(16, 2);
pinMode(upButton, INPUT);
pinMode(startButton, INPUT);
pinMode(downButton, INPUT);
pinMode(A0, OUTPUT); // LED 1
pinMode(A1, OUTPUT); // LED 2
pinMode(A2, OUTPUT); // LED 3
}
void loop()
{
start:
// Read the SELECT pin
if (WhichScreen == 1) {
buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) {
digitalWrite(ledPin, buttonState);
delay(2000);
digitalWrite(ledPin, LOW);
}
}
if (WhichScreen == 4) {
buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) {
// digitalWrite(ledPin2, buttonState);
// delay(5000);
// digitalWrite(ledPin2, LOW);
lcd.begin(16, 2);
minutes = 00; //start min
seconds = 05; //start seconds
digitalWrite(ledPin, buttonState);
lcd.print("P1-AMBER");
timer();
// Function SHOULD return to here when reaches zero
digitalWrite(ledPin, LOW);
minutes = 00; //start min
seconds = 05; //start seconds
lcd.print("P1-DARK RED");
timer();
}
}
if (hasChanged == true) {
switch (WhichScreen) {
case 0:
{
lcd.clear();
lcd.setCursor(2, 0); // Column, line
lcd.print("LIGHT THERAPY");
lcd.setCursor(2, 1);
lcd.print("PANEL V1.01");
delay(2500); // will be removed once relays are installed
lcd.clear();
lcd.setCursor(4, 0); // Column, line
lcd.print("WELCOME");
lcd.setCursor(1, 1);
lcd.print("GARY & TRACEY");
delay(2500); // will be removed once relays are installed
WhichScreen++;
program1();
}
break;
case 1:
{
program1();
}
break;
case 2:
{
program2();
}
break;
case 3:
{
program3();
}
break;
case 4:
{
program4();
}
break;
case 5:
{
program5();
}
break;
case 6:
{
program6();
}
break;
case 7:
{
program7();
}
break;
case 8:
{
program8();
}
break;
case 9:
{
program9();
}
break;
}
}
//-------------------------------
// BEGIN of the switch debouncing code
int reading = digitalRead(upButton);
if (reading != lastSelectState) {
// reset the debouncing timer
lastDebounceTime = millis();
}
if ((millis() - lastDebounceTime) > debounceDelay) {
// whatever the reading is at, it's been there for longer
// than the debounce delay, so take it as the actual current state:
// if the button state has changed:
if (reading != selectState) {
selectState = reading;
// only toggle the LED if the new button state is HIGH
if (selectState == HIGH) {
hasChanged = true;
WhichScreen++;
}
} else {
hasChanged = false;
}
}
lastSelectState = reading;
// END of the switch Debouncing code
// --------------------------------------
if (WhichScreen > 9) {
WhichScreen = 1;
}
}
void program1()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 1 (P1)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program2()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 2 (P2)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program3()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 3 (P3)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program4()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 4 (P4)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program5()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 5 (P5)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program6()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 6 (P6)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program7()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 7 (P7)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program8()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 8 (P8)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void program9()
{
lcd.clear();
lcd.setCursor(1, 0); // Column, line
lcd.print("PROGRAM 9 (P9)");
lcd.setCursor(3, 1);
lcd.print("14 Minutes");
}
void stepDown() {
if (seconds > 0) {
seconds -= 1;
} else {
if (minutes > 0) {
seconds = 59;
minutes -= 1;
} else {
if (hours > 0) {
seconds = 59;
minutes = 59;
hours -= 1;
} else {
//trigger();
}
}
}
}
void timer() {
delay(150);
while (hours > 0 || minutes > 0 || seconds >= 0) {
lcd.setCursor(0, 2);
//(hours < 10) ? lcd.print("0") : NULL;
// lcd.print(hours);
//lcd.print(":");
lcd.print("TIME LEFT: ");
(minutes < 10) ? lcd.print("0") : NULL;
lcd.print(minutes);
lcd.print(":");
(seconds < 10) ? lcd.print("0") : NULL;
lcd.print(seconds);
lcd.display();
stepDown();
delay(1000);
}
}
void trigger() {
lcd.clear(); // clears the screen and buffer
lcd.setCursor(6, 0); // set timer position on lcd for end.
lcd.print("TIMES UP");
lcd.setCursor(6, 1); // set timer position on lcd for end.
lcd.print("NUMBER 4");
delay(1000);
lcd.display();
}
Sorry it's a bit messy and all over the place, I'm also sure it's not flowing very well either but it works mostly lol.
Any and all help much appreciated, and thank you in advance.

Answer 1

In your timer function. You have a loop condition hours > 0 || minutes > 0 || seconds >= 0. Since your seconds is always greater than 0, you have a infinite loop in timer.
As you can see, seconds does not decrease seconds == 0.
void stepDown() {
if (seconds > 0) {
seconds -= 1;
} else {
if (minutes > 0) {
seconds = 59;
minutes -= 1;
} else {
if (hours > 0) {
seconds = 59;
minutes = 59;
hours -= 1;
} else {
//trigger();
}
}
}
}