void setup() {
  Serial.begin(115200);
}

void loop() {
  float volts = (5 * (analogRead(A0) / 1024.0));
  if (volts > 0)
  {
    Serial.print(volts);
    Serial.println(" vdc");
    delay(250);
  }
}


analog_switch.ino

diagram.json

#include "wokwi-api.h"
#include <stdio.h>
#include <stdlib.h>

typedef struct 
{
  pin_t IN1;
  pin_t IN2;
  pin_t IN3;
  pin_t IN4;
  pin_t IN5;
  pin_t OUT;
} chip_state_t;

static void chip_timer_callback(void *user_data) 
{
  chip_state_t *chip = (chip_state_t*)user_data;
  pin_t pins [5] = {
    chip->IN1, chip->IN2, chip->IN3, chip->IN4, chip->IN5
  };
  uint8_t input = 0;
  for (uint8_t i = 0; i < 5; ++i)
  {
    if (pin_read(pins[i]))
    {
      input = i + 1;
      break;
    }
  }
  pin_dac_write(chip->OUT, input);
}

void chip_init(void) 
{
  chip_state_t *chip_data = malloc(sizeof(chip_state_t));
  chip_data->IN1 = pin_init("IN1", INPUT);
  chip_data->IN2 = pin_init("IN2", INPUT);
  chip_data->IN3 = pin_init("IN3", INPUT);
  chip_data->IN4 = pin_init("IN4", INPUT);
  chip_data->IN5 = pin_init("IN5", INPUT);
  chip_data->OUT = pin_init("OUT", ANALOG);

  const timer_config_t config = 
  {
    .callback = chip_timer_callback,
    .user_data = chip_data,
  };

  timer_t timer_id = timer_init(&config);
  timer_start(timer_id, 1000, true);
}
