How to use millis on traffic light controller in Arduino - arduino

Question

I'm doing a smart city project with my Arduino and I have a question. I have created 2 functions and one of them is the traffic light controller and I use the delay() to make them have the right delays between them. But I have a problem. I call both of the functions inside loop(), but one of them only runs when the other is finished. Is there any way to run them both? I've seen people using millis().
My code:
int smartled1 = 13;
int smartled2 = 12;
int smartled3 = 11;
int smartled4 = 10;
int smartled5 = 9;
int smartled6 = 8;
int smartled7 = 7;
int smartled8 = 6;
int smartled9 = 50;
int smartled10 = 51;
int smartled11 = 52;
int smartled12 = 53;// Pin para ligar o led
int sensorPin = A0; // Seleção do pin de entrada do LDR
int sensorValor = 0; // Variavel de armazenamento do LDR inicializada a 0
int semaforo1[]= {22, 24, 26};
int semaforo2[]= {5, 4, 3};
int semaforo3[]= {29, 31, 33};
int semaforo4[]= {28, 30, 32};
int Delayvermelho = 5000;
int Delayamarelo = 2000;
void setup() {
Serial.begin(9600); // Define a porta serie para comunicação
pinMode(smartled1, OUTPUT);
pinMode(smartled2, OUTPUT);
pinMode(smartled3, OUTPUT);
pinMode(smartled4, OUTPUT);
pinMode(smartled5, OUTPUT);
pinMode(smartled6, OUTPUT);
pinMode(smartled7, OUTPUT);
pinMode(smartled8, OUTPUT);
pinMode(smartled9, OUTPUT);
pinMode(smartled10, OUTPUT);
pinMode(smartled11, OUTPUT);
pinMode(smartled12, OUTPUT);// Define o pin do Led como saída
for (int i = 0; i < 3; i++) {
pinMode(semaforo1[i], OUTPUT);
pinMode(semaforo2[i], OUTPUT);
pinMode(semaforo3[i], OUTPUT);
pinMode(semaforo4[i], OUTPUT);
}
}
void loop() {
smart_lights();
semaforos_cruzamento();
}
void semaforos_cruzamento(){
// Making Green LED at signal 1 and red LED's at other signal HIGH
digitalWrite(semaforo1[2], HIGH);
digitalWrite(semaforo1[0], LOW);
digitalWrite(semaforo2[0], HIGH);
digitalWrite(semaforo3[0], HIGH);
digitalWrite(semaforo4[0], HIGH);
delay(Delayvermelho);
// Making Green LED at signal 1 LOW and making yellow LED at signal 1 HIGH for 2 seconds
digitalWrite(semaforo1[1], HIGH);
digitalWrite(semaforo1[2], LOW);
delay(Delayamarelo);
digitalWrite(semaforo1[1], LOW);
// Making Green LED at signal 2 and red LED's at other signal HIGH
digitalWrite(semaforo1[0], HIGH);
digitalWrite(semaforo2[2], HIGH);
digitalWrite(semaforo2[0], LOW);
digitalWrite(semaforo3[0], HIGH);
digitalWrite(semaforo4[0], HIGH);
delay(Delayvermelho);
// Making Green LED at signal 2 LOW and making yellow LED at signal 2 HIGH for 2 seconds
digitalWrite(semaforo2[1], HIGH);
digitalWrite(semaforo2[2], LOW);
delay(Delayamarelo);
digitalWrite(semaforo2[1], LOW);
// Making Green LED at signal 3 and red LED's at other signal HIGH
digitalWrite(semaforo1[0], HIGH);
digitalWrite(semaforo2[0], HIGH);
digitalWrite(semaforo3[2], HIGH);
digitalWrite(semaforo3[0], LOW);
digitalWrite(semaforo4[0], HIGH);
delay(Delayvermelho);
// Making Green LED at signal 3 LOW and making yellow LED at signal 3 HIGH for 2 seconds
digitalWrite(semaforo3[1], HIGH);
digitalWrite(semaforo3[2], LOW);
delay(Delayamarelo);
digitalWrite(semaforo3[1], LOW);
// Making Green LED at signal 4 and red LED's at other signal HIGH
digitalWrite(semaforo1[0], HIGH);
digitalWrite(semaforo2[0], HIGH);
digitalWrite(semaforo3[0], HIGH);
digitalWrite(semaforo4[2], HIGH);
digitalWrite(semaforo4[0], LOW);
delay(Delayvermelho);
// Making Green LED at signal 4 LOW and making yellow LED at signal 4 HIGH for 2 seconds
digitalWrite(semaforo4[1], HIGH);
digitalWrite(semaforo4[2], LOW);
delay(Delayamarelo);
digitalWrite(semaforo4[1], LOW);
}
void smart_lights(){
int sensorValor = analogRead(sensorPin);// Lê o valor fornecido pelo LDR
Serial.println(sensorValor);//Imprime os valores provenientes do sensor na ecrã
// Caso o valor lido na porta analógica A5 seja maior do que
// 800, acende o LED
// Ajuste o valor abaixo de acordo com o circuito
if (sensorValor < 400)
{
digitalWrite(smartled1, HIGH);
digitalWrite(smartled2, HIGH);
digitalWrite(smartled3, HIGH);
digitalWrite(smartled4, HIGH);
digitalWrite(smartled5, HIGH);
digitalWrite(smartled6, HIGH);
digitalWrite(smartled7, HIGH);
digitalWrite(smartled8, HIGH);
digitalWrite(smartled9, HIGH);
digitalWrite(smartled10, HIGH);
digitalWrite(smartled11, HIGH);
digitalWrite(smartled12, HIGH);
}
else //Caso contrário, apaga o led
{
digitalWrite(smartled1, LOW);
digitalWrite(smartled2, LOW);
digitalWrite(smartled3, LOW);
digitalWrite(smartled4, LOW);
digitalWrite(smartled5, LOW);
digitalWrite(smartled6, LOW);
digitalWrite(smartled7, LOW);
digitalWrite(smartled8, LOW);
digitalWrite(smartled9, LOW);
digitalWrite(smartled10, LOW);
digitalWrite(smartled11, LOW);
digitalWrite(smartled12, LOW);
}
}

Answer 1

Yes, you can use state machines.
Example:
// totally randon delays. Prime to each other.
static const unsigned char MY_EVENT_TIMEOUT = 100; // in milliseconds.
static const unsigned int HIS_EVENT_TIMEOUT = 2533; // in milliseconds.
// setup two sta=te machines. In this example both state machines will simply
// wait a bit before toggling between two states.
// state machines consist of different state values, a state variable, and some data
enum MyEventState {
my_event_state_initial, // we'll just start timing
my_event_state_1,
my_event_state_2,
/* and so on... */
};
MyEventState my_state = my_state_initial;
unsigned char my_event_timestamp; // largest my_event delay is less than 255 ms
// second state machine.
enum HisEventState {
his_event_state_iinitial, // we'll wait for some external event
his_event_state_1,
his_event_state_2,
/* more states if you need */
};
HisEventState his_state = his_state_initial;
unsigned int his_event_timestamp; // largest his_event delay is less than 65535 ms
void my_event_handler()
{
switch (my_state)
{
case my_event_state_initial:
// initialize our timestamp and go straight to state 1
my_event_timestamp = (unsigned char)millis();
my_state = my_event_state_1;
// passing though to execute next state handler immediately
case my_event_state_1:
// in real application, you'd likely CHECK for a triggering event first
// and check millis() for timeouts, etc. Using different states to
// check for time out... Note the use of subtraction of UNSIGNED
// values to avoid rollover issues altogether
// the extra cast is the correct way to to it. C++ subtraction MAY
// return an unsigned int, according to the standard. In practice, it
// does not happens for 8 and 16-bit MCUs.
// no matter what you do, do not wait, poll your input line, or
// check if there are bytes on the serial buffer, do not block.
if ((unsigned char)((unsigned char)millis() - my_event_timestamp) < MY_EVENT_TIMEOUT)
{
// not enough time has elapsed, nothing to do, so return
return;
}
my_event_timestamp = (unsigned char)millis(); // get a time stamp
my_state = my_event_state_2; // change state
// passing though to execute next state handler immediately
case my_event_state_2:
// it's always the same logic in this simple state machine,
// but you can put any logic you want here to turn one light on or off,
// check inputs, etc..
if ((unsigned char)millis() - my_event_timestamp < MY_EVENT_TIMEOUT)
{
// not enough time has elapsed, nothing to do, so return
return;
}
my_event_timestamp = (unsigned char)millis(); // get a time stamp
my_state = my_event_state_1; // change state
// we're done. the handler for state 1 will execute the next time
// loop() is called.
// This would be the place you could find an infamous goto within a
// switch blck, if timing needs to be suoer duper extra tight.
// It does happen sometimes, but rarely.
return;
}
}
void his_event_handler()
{
// this is the same logic, but with a different beat.
// since these handlers do not block for timers or events
// the handlers appear to run 'concurrently'
switch (his_state)
{
case his_event_state_initial:
// initialize our timestamp and go straight to state 1
his_event_timestamp = (unsigned int)millis();
his_state = his_event_state_1;
// passing though to execute next state handler immediately
case his_event_state_1:
if ((unsigned int)millis() - his_event_timestamp < HIS_EVENT_TIMEOUT)
{
// not enough time has elapsed, nothing to do, so return
return;
}
his_event_timestamp = (unsigned int)millis(); // get a time stamp
his_state = his_event_state_2; // change state
// passing though to execute next state handler immediately
case his_event_state_2:
if ((unsigned int)millis() - his_event_timestamp < HIS_EVENT_TIMEOUT)
{
// not enough time has elapsed, nothing to do, so return
return;
}
his_event_timestamp = (unsigned int)millis(); // get a time stamp
his_state = his_event_state_1; // change state
// we're done. the handler for state 1 will execute the next time
// loop() is called.
return;
}
}
void setup()
{
}
void loop() {
// call our concurrent state machines
my_event_handler();
his_event_handler();
/* some other non-blocking code... */
}