#include <Arduino.h>
#include <StateMachine.h>
#define WITH_DEBUG
#include <DebugUtil.h>

// Initialization
...

class TrafficLight : public StateMachine {
    public:
        using StateMachine::StateMachine;
        State STOP() {
            if (isStateUpdated()) {
                RED_ON();
                YELLOW_OFF();
                GREEN_OFF();
                DEBUG("STOP");
                return;
            }
            if (isTimeout(10000)) {
                setState((PState) &TrafficLight::WAIT);
                return;
            }
        };
        State WAIT() {
            if (isStateUpdated()) {
                RED_ON();
                YELLOW_ON();
                GREEN_OFF();
                DEBUG("WAIT");
                return;
            }
            if (isTimeout(2000)) {
                setState((PState) &TrafficLight::DRIVE);
                return;
            }
        };
        ...
};

TrafficLight trafficLight((PState) &TrafficLight::STOP);

void loop() {
    trafficLight.loop();
    // Other code
    ...
}

0: TrafficLight.ino:25 STOP - STOP
10001: TrafficLight.ino:38 WAIT - WAIT
12002: TrafficLight.ino:51 DRIVE - DRIVE
22003: TrafficLight.ino:64 SLOW - SLOW
24004: TrafficLight.ino:25 STOP - STOP
34006: TrafficLight.ino:38 WAIT - WAIT
36007: TrafficLight.ino:51 DRIVE - DRIVE
...