ESP32 IoT Room Station (Relay + DHT22)

1// ─────────────────────────────────────────
2//   BlueGrays · bluegrays.com
3//   ESP32 IoT Room Station (Relay + DHT22)
4// ─────────────────────────────────────────
5// The "Room station" IoT template from the BlueGrays app: switch a lamp
6// from your phone with a relay while the DHT22 sends the room temperature
7// and humidity to the app every 2 seconds. Ohmi prepares the real code in
8// the app with your own device key (Workshop › Devices › Add a device);
9// the code here is an example, the device key and Wi-Fi details are
10// placeholders. Library Manager: BlueGraysIoT (with its dependencies). The
11// board only joins 2.4 GHz Wi-Fi networks. The relay switches on LOW. Only
12// wire a mains lamp with someone experienced; try with an LED first.
13//
14// Pins:
15//   GPIO26 -> Relay module IN
16//   5V, GND -> Relay module VCC, GND
17//   Relay COM -> 5V, NO -> 220 ohm -> LED anode, LED cathode -> GND
18//   GPIO4 -> DHT22 OUT (data)
19//   3V3, GND -> DHT22 VCC, GND
20//   Pico W: relay IN GP15, DHT22 OUT GP16
21
22/*
23 * Room station · BlueGrays IoT
24 * BlueGrays · bluegrays.com
25 * Do not share this code: it contains your device key and Wi-Fi password.
26 */
27
28#include <BlueGraysIoT.h>
29#include <DHT.h>
30
31const char *DEVICE_KEY = "YOUR_DEVICE_KEY";
32const char *WIFI_NAME = "YOUR_WIFI_NAME";
33const char *WIFI_PASSWORD = "YOUR_WIFI_PASSWORD";
34
35BlueGraysIoT bg(DEVICE_KEY);
36
37const int RELAY_PIN = 26;
38const bool RELAY_ACTIVE_LOW = true;  // most relay modules switch on LOW
39void setRelay(bool on) { digitalWrite(RELAY_PIN, (on != RELAY_ACTIVE_LOW) ? HIGH : LOW); }
40DHT dht(4, DHT22);
41unsigned long lastReadMs = 0;
42
43void setup() {
44  Serial.begin(115200);
45  pinMode(RELAY_PIN, OUTPUT);
46  setRelay(false);
47  bg.onSwitch("lamba", setRelay);
48  dht.begin();
49  bg.setDeadband("sicaklik", 0.1);
50  bg.setDeadband("nem", 1.0);
51  bg.setDebug(Serial);
52  bg.setLanguage(BG_LANG_EN);
53  bg.begin(WIFI_NAME, WIFI_PASSWORD);
54}
55
56void loop() {
57  bg.loop();  // avoid long delay() calls here
58  if (millis() - lastReadMs >= 2000) {
59    lastReadMs = millis();
60    bg.send("sicaklik", dht.readTemperature());
61    bg.send("nem", dht.readHumidity());
62  }
63}
64