// In diagram.json these lines
//    [ "pico:GP0", "$serialMonitor:RX", "", [] ],
//    [ "pico:GP1", "$serialMonitor:TX", "", [] ],
// were removed, so that 
//     Serial instead of Serial1
// can be used. (RK)

#define RASPI_PICO_W  // so that settings.h works for all boards


#include "settings.h"
#include "Trafficlights_in_C.h"

void setup() 
{
  Serial.begin(115200); // 
  Serial.println("Raspberry Pi Pico circuit for Embedded C++ (www.rkaiser.de)");
  N_Settings::show_gcc_version();
  N_trafficlights_in_C::setup();
}

int counter = 0;

void loop()
{
  Serial.println(counter);
  delay(1000);
  counter++;
  N_trafficlights_in_C::loop();
}


sketch.ino

diagram.json

namespace N_Settings // for the Wokwi circuits from section ???
{
// Use the predefined onboard-LED symbols if they are defined
// Uncomment the line with the board you are using:
#ifdef RASPI_PICO_W
const uint32_t pin_onboard_LED = PICO_DEFAULT_LED_PIN; // #define PICO_DEFAULT_LED_PIN 25
#elif defined (ESP32)
const uint32_t pin_onboard_LED = 2; // ESP32
#elif defined (STM32_NUCLEO)
const uint32_t pin_onboard_LED = LED_BUILTIN; // STM32 Nucleo 32: 23, 64: 52, 144: 117
#endif

// global variables should always be const (C++ core guidelines I.2, R.6)
const uint32_t pin_red_light = 2; // instead of #define pin_red_light 2, here with =
const uint32_t pin_yellow_light = { 4 }; // C++11 initializer list with =
const uint32_t pin_green_light{ 5 };   // C++11 initializer list, prefer this notation

const uint32_t pin_potentiometer = { 26 };
const uint32_t pin_HC_SR04_trigger = 12;
const uint32_t pin_HC_SR04_echo = 13;
const uint32_t pin_pushButton = 14;

// there will be examples where the duration needs to be changed
uint32_t duration_red_phase{ 5000 };        // not const,
uint32_t duration_red_yellow_phase{ 1000 }; // so that
uint32_t duration_green_phase{ 5000 };      // they can
uint32_t duration_yellow_phase{ 1000 };     // be changed

void show_gcc_version()
{
  Serial.print("GCC Version: ");
  Serial.print(__GNUC__);
  Serial.print(".");
  Serial.print(__GNUC_MINOR__);
  Serial.print(".");
  Serial.println(__GNUC_PATCHLEVEL__);
  printf("GCC Version: %d.%d.%d\n",__GNUC__,__GNUC_MINOR__,__GNUC_PATCHLEVEL__);
}


}

settings.h

#define RED 2
#define YELLOW 4
#define GREEN 5
namespace N_trafficlights_in_C 
{

void setup()
{
  Serial.begin(115200);
  while (!Serial) { // wait for the serial port to connect. Needed for native USB port only
    ;
  }
  pinMode(RED, OUTPUT);    // configure pin 2 as output
  pinMode(YELLOW, OUTPUT); // configure pin 4 as output
  pinMode(GREEN, OUTPUT);  // configure pin 5 as output
  Serial.println("setup traffic lights version 1 in C ");
}

void loop()
{
  digitalWrite(RED, HIGH);    // set voltage to pin 2 (connected to the red LED), red LED lights up
  delay(6000);                // the program waits until 6 seconds are over
  digitalWrite(YELLOW, HIGH); // turn the yellow LED on,
  delay(1000);                // wait 1 second, red is still turned on
  digitalWrite(RED, LOW);     // set voltage to 0 Volt at pin 2, turns red LED off
  digitalWrite(YELLOW, LOW);  // turns the yellow LED off
  digitalWrite(GREEN, HIGH);  // turns the green LED on
  delay(5000);                // green LED lights for 5 seconds
  digitalWrite(GREEN, LOW);   // turns the green LED off
  digitalWrite(YELLOW, HIGH); // turns the yellow LED on
  delay(1000);                // yellow LED remains on for 1 second
  digitalWrite(YELLOW, LOW);  // turns the yellow LED off
}

}