Komponen yang Dibutuhkan:
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ESP32
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Sensor NTC + resistor (untuk voltage divider)
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LCD 16x2 + I2C module
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Breadboard dan kabel jumper
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Internet (WiFi)
(Vcc) ---- [10K Resistor] ----+---- [NTC] ---- GND
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(Analog input ke ESP32, misal GPIO34)
Kode Program ESP32 (Arduino IDE)
Instalasi Library:
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LiquidCrystal_I2Cuntuk LCD -
Gunakan Arduino IDE dengan board ESP32 diaktifkan
#include <WiFi.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// Konfigurasi WiFi
const char* ssid = "NAMA_WIFI";
const char* password = "PASSWORD_WIFI";
// Konfigurasi sensor NTC
const int ntcPin = 34; // Analog pin
const float seriesResistor = 10000.0;
const float nominalResistance = 10000.0;
const float nominalTemperature = 25.0;
const float bCoefficient = 3950.0;
// LCD I2C
LiquidCrystal_I2C lcd(0x27, 16, 2);
// Server web ESP32
WiFiServer server(80);
// Fungsi untuk menghitung suhu dari pembacaan NTC
float readTemperature() {
int analogValue = analogRead(ntcPin);
float voltage = analogValue / 4095.0 * 3.3;
float resistance = (3.3 - voltage) * seriesResistor / voltage;
float steinhart;
steinhart = resistance / nominalResistance; // (R/Ro)
steinhart = log(steinhart); // ln(R/Ro)
steinhart /= bCoefficient; // 1/B * ln(R/Ro)
steinhart += 1.0 / (nominalTemperature + 273.15); // + (1/To)
steinhart = 1.0 / steinhart; // Invert
steinhart -= 273.15; // convert to Celsius
return steinhart;
}
void setup() {
Serial.begin(115200);
Wire.begin(21, 22); // SDA, SCL
lcd.begin();
lcd.backlight();
// Koneksi WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("Connected to WiFi");
Serial.println(WiFi.localIP());
server.begin();
}
void loop() {
float temperature = readTemperature();
lcd.setCursor(0, 0);
lcd.print("Suhu: ");
lcd.print(temperature, 1);
lcd.print(" C ");
WiFiClient client = server.available();
if (client) {
Serial.println("Client connected");
String response = "<!DOCTYPE html><html><head><meta http-equiv='refresh' content='5'/>";
response += "<title>Suhu Ruangan</title></head><body>";
response += "<h1>Suhu: ";
response += temperature;
response += " °C</h1></body></html>";
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println();
client.println(response);
client.stop();
}
delay(1000);
}
Cara Akses Web Interface (AJAX)
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Upload kode ke ESP32.
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Buka Serial Monitor → Catat alamat IP (misalnya
192.168.1.42) -
Buka browser dan akses IP tersebut.
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Web akan menampilkan suhu yang diperbarui otomatis setiap detik tanpa reload
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