ESP32 con WiFiManager, OLED y DHT22

#include <WiFi.h>
#include <WiFiManager.h>
#include <U8g2lib.h>
#include <Wire.h>
#include "DHTesp.h"

const int PIN_DHT  = 4;
const int PIN_LDR  = 34;
const int PIN_BTN1 = 25;
const int PIN_BTN2 = 26;
const int LED_R = 16, LED_A = 17, LED_V = 18;
const int LED_LUZ = 19;

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE);
DHTesp dht;
WiFiManager wm;
bool pagina2 = false;

void pantalla(const char* a, const char* b, const char* c) {
  u8g2.clearBuffer();
  u8g2.setFont(u8g2_font_6x12_tf);
  u8g2.drawStr(0, 14, a);
  u8g2.drawStr(0, 34, b);
  u8g2.drawStr(0, 54, c);
  u8g2.sendBuffer();
}

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);
  u8g2.begin();
  dht.setup(PIN_DHT, DHTesp::DHT22);
  pinMode(PIN_BTN1, INPUT);
  pinMode(PIN_BTN2, INPUT);
  pinMode(LED_R, OUTPUT); pinMode(LED_A, OUTPUT);
  pinMode(LED_V, OUTPUT); pinMode(LED_LUZ, OUTPUT);
  pantalla("Conectando WiFi...", "", "");
  if (!wm.autoConnect("ESP32-Config")) ESP.restart();
}

void loop() {
  if (digitalRead(PIN_BTN1) == HIGH) {
    wm.resetSettings();
    delay(500);
    ESP.restart();
  }
  if (digitalRead(PIN_BTN2) == HIGH) { pagina2 = !pagina2; delay(250); }

  TempAndHumidity d = dht.getTempAndHumidity();
  int luz = analogRead(PIN_LDR);
  if (dht.getStatus() == DHTesp::ERROR_NONE) {
    digitalWrite(LED_V, d.temperature <= 24);
    digitalWrite(LED_A, d.temperature > 24 && d.temperature <= 30);
    digitalWrite(LED_R, d.temperature > 30);
  }
  digitalWrite(LED_LUZ, luz < 1000);

  char l1[24], l2[24], l3[24];
  if (pagina2) {
    snprintf(l1, sizeof(l1), "ADC34: %d", luz);
    snprintf(l2, sizeof(l2), "%.2f V", luz * 3.3 / 4095);
    pantalla(l1, l2, "Pagina 2");
  } else {
    snprintf(l1, sizeof(l1), "T: %.1f C  H: %.0f%%", d.temperature, d.humidity);
    snprintf(l2, sizeof(l2), "Luz: %d", luz);
    snprintf(l3, sizeof(l3), "%s", WiFi.localIP().toString().c_str());
    pantalla(l1, l2, l3);
  }
  delay(2000);
}

En el IDE de Arduino: Herramientas → Gestionar bibliotecas, y busca:

WiFiManager  (autor: tzapu)
U8g2         (autor: oliver)
DHT sensor library for ESPx   (autor: beegee_tokyo, incluye DHTesp)

Placa: «ESP32 Dev Module». Si falla la subida, mantén pulsado el botón BOOT del ESP32 al empezar a subir.