<![CDATA[The microclimatic environment during the brooding phase (Days 1–14 post-hatch) is the single most decisive factor governing the survival, growth kinetics, and physiological health of Kampung Unggul Balitbangtan (KUB) Day-Old Chicks (DOC). Due to immature thermoregulatory centers and the absence of thermal insulation, DOCs are poikilothermic and highly susceptible to ambient temperature drops and humidity swings. Conventional bang-bang (ON-OFF) and manual control systems suffer from severe thermal oscillations, actuator chatter, high energy waste, and inrush current surges. This research designs, implements, and rigorously analyzes an intelligent closed-loop microclimate regulation system driven by an embedded Mamdani Fuzzy Logic Controller (FLC) executed on an ESP32 dual-core 32-bit microcontroller. The sensory architecture integrates a high-precision Aosong DHT20 sensor over a deterministic hardware I2C bus for concurrent temperature and relative humidity (RH) acquisition, coupled with a 5:1 metal-film resistive voltage divider monitoring the primary 12V DC power supply rail. The FLC processes error e(T), error rate Δe(T), and RH to modulate ceramic infrared heaters via solid-state zero-crossing phase dimming and variable-speed 12V DC exhaust ventilation. Static metrological calibration against Fluke 971 and Keysight 34461A standards established a Mean Absolute Error (MAE) of 0.182 °C (R² = 0.9998) for temperature, 0.740% for RH (R² = 0.9993), and 0.021 V for power supply rail voltage (R² = 0.9999). Dynamic 24-hour testing under tropical ambient disturbances (22.5–33.8 °C; 56.4–94.6% RH) proved that the proposed FLC maintained brooder temperature with extreme precision at 33.51 ± 0.14 °C (Thermal Stability Index TSI = 99.8%) and RH at 65.2 ± 1.4%, effectively eliminating the ±0.75 °C overshoot/undershoot cycles typical of hysteresis controllers. Biological validation across a 14-day live trial with n = 300 KUB DOC chicks demonstrated that the Fuzzy IoT system suppressed cumulative mortality to 0.67% (vs. 8.00% conventional and 3.00% ON-OFF), increased final Day-14 mean body weight to 374.2 ± 11.6 g (+51.4% over conventional), achieved an extraordinary Feed Conversion Ratio (FCR) of 1.18 (vs. 1.62 conventional), and reduced electrical consumption by 48.6%. The study confirms that fuzzy logic environmental modulation provides superior microclimate stability, animal welfare, and energetic efficiency for smart precision poultry farming.]]>
