diff --git a/UCPSMain/UCPSMain.ino b/UCPSMain/UCPSMain.ino
new file mode 100644
index 0000000..db18bef
--- /dev/null
+++ b/UCPSMain/UCPSMain.ino
@@ -0,0 +1,156 @@
+#include <LiquidCrystal.h>
+#include <dht_nonblocking.h>
+#include <SoftwareSerial.h>
+#include <WiFiEsp.h>
+
+// Wifi (Hotspot)
+const char wifiSSID[] = "FreeWifi";
+const char wifiPASS[] = "temppassword";
+
+// ESP8266 (Wifi module, AT firmware)
+SoftwareSerial wifiSerial(2, 3); // RX = 2, TX = 3
+WiFiEspClient client;
+
+// LCD Display
+#define DHT_SENSOR_TYPE DHT_TYPE_11
+static const int DHT_SENSOR_PIN = A1;
+DHT_nonblocking dht_sensor(DHT_SENSxOR_PIN, DHT_SENSOR_TYPE);
+
+LiquidCrystal lcd(7, 8, 9, 10, 11, 12); // RS, EN, D4, D5, D6, D7
+
+// Light sensor and LEDs
+int lightPin = A0;  // LDR
+int dataPin  = 4;   // DS
+int latchPin = 5;   // ST_CP
+int clockPin = 6;   // SH_CP
+int leds     = 0;
+
+// API
+const float NO_TEMP = -999.0;
+const unsigned long API_INTERVAL   = 600000UL; // 10m
+const unsigned long RETRY_INTERVAL = 30000UL;  // 30s
+unsigned long lastApiFetch = 0;
+unsigned long fetchInterval = API_INTERVAL;
+float outdoorTemp = NO_TEMP;
+
+// Connect to hotspot if not connected, then fetch the current temperature
+float fetchOutdoorTemp() {
+  if (WiFi.status() != WL_CONNECTED) {
+    WiFi.begin(wifiSSID, wifiPASS);
+    if (WiFi.status() != WL_CONNECTED) return NO_TEMP;
+  }
+
+  client.setTimeout(5000);
+  if (!client.connect("api.open-meteo.com", 80)) return NO_TEMP;
+
+  client.print(F("GET /v1/forecast?latitude=49.46998&longitude=8.4819&current=temperature_2m HTTP/1.1\r\n"
+                 "Host: api.open-meteo.com\r\n"
+                 "Connection: close\r\n"
+                 "\r\n"));
+
+  // Skip ahead to the number in {"current":{..."temperature_2m":12.3}}
+  float t = NO_TEMP;
+  if (client.find("\"current\":") && client.find("\"temperature_2m\":")) {
+    t = client.parseFloat();
+  }
+  client.stop();
+  return t;
+}
+
+// Write to LCD display
+void lcdLine(uint8_t row, const char *text) {
+  lcd.setCursor(0, row);
+  uint8_t i = 0;
+  for (; text[i] != '\0' && i < 16; i++) lcd.write(text[i]);
+  for (; i < 16; i++) lcd.write(' ');
+}
+
+// LEDs for light sensor
+void updateShiftRegister() {
+  digitalWrite(latchPin, LOW);
+  shiftOut(dataPin, clockPin, LSBFIRST, leds);
+  digitalWrite(latchPin, HIGH);
+}
+
+// Measure temperature and humidity
+static bool measure_environment(float *temp, float *hum) {
+  static unsigned long timestamp = millis();
+
+  if (millis() - timestamp > 3000ul) {
+    if (dht_sensor.measure(temp, hum) == true) {
+      timestamp = millis();
+      return true;
+    }
+  }
+  return false;
+}
+
+void setup() {
+  pinMode(latchPin, OUTPUT);
+  pinMode(dataPin, OUTPUT);
+  pinMode(clockPin, OUTPUT);
+
+  Serial.begin(115200);
+  lcd.begin(16, 2);
+  lcdLine(0, "Connecting WiFi");
+  lcdLine(1, "");
+
+  wifiSerial.begin(9600);
+  WiFi.init(&wifiSerial);
+
+  if (WiFi.status() == WL_NO_SHIELD) {
+    lcdLine(0, "ESP not found");
+    delay(2000);
+  }
+
+  outdoorTemp = fetchOutdoorTemp();
+  lastApiFetch = millis();
+  fetchInterval = (outdoorTemp == NO_TEMP) ? RETRY_INTERVAL : API_INTERVAL;
+  lcd.clear();
+}
+
+void loop() {
+  float indoorTemp;
+  float indoorHum;
+
+  if (measure_environment(&indoorTemp, &indoorHum) == true) {
+    char tempStr[10];
+    dtostrf(indoorTemp, 4, 1, tempStr);
+    char line0[20];
+    snprintf(line0, sizeof(line0), "In:  %s C", tempStr);
+    lcdLine(0, line0);
+  }
+
+  if (millis() - lastApiFetch >= fetchInterval) {
+    float t = fetchOutdoorTemp();
+    lastApiFetch = millis();
+    if (t != NO_TEMP) {
+      outdoorTemp = t;
+      fetchInterval = API_INTERVAL;
+    } else {
+      fetchInterval = RETRY_INTERVAL;
+    }
+  }
+
+  if (outdoorTemp != NO_TEMP) {
+    char outStr[10];
+    dtostrf(outdoorTemp, 4, 1, outStr);
+    char line1[20];
+    snprintf(line1, sizeof(line1), "Out: %s C", outStr);
+    lcdLine(1, line1);
+  } else {
+    lcdLine(1, "Out: API Error");
+  }
+
+  int reading = analogRead(lightPin);
+  int numLEDSLit = reading / 57;
+
+  if (numLEDSLit > 8) numLEDSLit = 8;
+  leds = 0;
+  for (int i = 0; i < numLEDSLit; i++) {
+    leds = leds + (1 << i);
+  }
+  updateShiftRegister();
+
+  delay(100);
+}