Prayer rooms and mosques in Islamic countries often rely on Air Conditioning (AC) units for climate control, constituting a significant portion of energy consumption. To address this, a cost-effective M5StickC IoT device with an integrated Infrared (IR) emitter and Real-Time Clock (RTC) is employed for automated AC control, eliminating the need for manual intervention. Programmed through the Arduino IDE, the IoT device autonomously calculates prayer times offline, aligns them with RTC time, and activates the AC unit before prayer, deactivating it after. Enhancing energy optimization, a Passive Infrared (PIR) sensor detects human motion near the AC unit, allowing the device to turn off the AC during prayer if no motion is detected. A user-friendly mobile application, operating offline via Bluetooth, updates the RTC module's time without internet dependency. Successfully tested in a prayer room with a Midea AC unit, the results demonstrate significant energy savings, making this economical solution highly impactful in reducing electricity bills.

IoT device; PIR sensor; Energy saving