Development of an IoT-Based Heat Index and UV Index Monitoring System Using ESP8266 in Sikka Regency Isma Alip, Zakaria Al Farizi, Nurfadilah, Isma Alip, Zakaria Al Farizi, Nurfadilah PISTON: Jurnal Teknologi Vol. 11 No. 1 2026 DOI 10.55679/pistonjt.v11i1.139