Esp-01 | 01s

Always buy ESP-01S unless you have a specific need for the original's smaller flash (almost never). For anything beyond two I/O pins, skip both and use ESP-12E/F, Wemos D1 Mini, or NodeMCU.

#define LED 2 // GPIO2, active LOW on ESP-01S void setup() pinMode(LED, OUTPUT); digitalWrite(LED, HIGH); // off esp-01 01s

void loop() digitalWrite(LED, LOW); // on delay(1000); digitalWrite(LED, HIGH); delay(1000); Always buy ESP-01S unless you have a specific

void loop() float h = dht.readHumidity(); float t = dht.readTemperature(); client.publish("sensor/temp", String(t).c_str()); delay(30000); skip both and use ESP-12E/F

DHT dht(DHTPIN, DHTTYPE); WiFiClient espClient; PubSubClient client(espClient);