21 MEDITERRANEAN PUBLICATION AND RESEARCH INTERNATIONAL INTERNATIONAL JOURNAL – AAE VOL. 08 NO. 5 – APRIL, 2025 EDITOR-IN-CHIEF Prof. Saeid Eslamian [IRAN] E-ISSN: 1115 – 831X P-ISSN: 3027-2963 DESIGN OF MICROCONTROLLER BASED SECURITY DOOR/RAIN DETECTOR USING MEMORY CARD KENNETH UGO UDEZE; & MEZUE FRANCIS CANICE TOCHUKWU Department of Electrical & Electronics Engineering, Federal Polytechnic Oko, Anambra State. Nigeria. Corresponding Author: princeken2003@gmail.com DOI: https://doi.org/10.70382/mejaaer.v8i5.015 Abstract dvances in technology led to the use of passwords in the door/gate mechanism but researchers approved that there is the human limitation in which the average human memory limit is at most nine-digit password combination and many users often write down password thus increasing the possibility of security breach. Hence to reduce or eliminate the access of unauthorized person to offices, at the administrative blocks, warehouses etc., the research to design a microcontroller-based security door detector using micro memory card and an automatic rain detector for the windows was conceived. This research is to provide a two-way factor authentication, which uses a card and a PIN code for door access authentication. The work also incorporates a rain detector for shutting the windows automatically when it rains. If the card is not recognized, access will not be granted or if the Pin entered is incorrect trice, the card will become unusable again and access is denied. Automatic shutting of the window is achieved through the use of a sensor and its associated circuit, which operates a motor that closes the window as soon as rain splashes on the sensor. When it stops raining and the water on A MPRI-JAAE INTERNATIONAL JOURNAL OF APPLIED & ADVANCED ENGINEERING RES. VOL. 08 NO. 5 - APRIL, 2025 E-ISSN: 1116 – 2716 P-ISSN: 3026-8214 Keywords: Rain Water, Rain Sensor, Buzzer, Microcontroller, keypad, motor, Transistors