Through the promptly expanding frequency of security incidents on the Internet of Things, intrusion detection systems have become a challenging issue to implement in IoT-enabled networks. Most of the developed intrusion detection systems are not very reliable due to the single or double-layer intrusion detection provision. The proposed and developed multilayer intrusion detection systems in this paper enhance the detection capabilities of intrusions detection for physical objects with alarm situations as well as object identification by echo signal characteristics. This will provide multilevel and reliable security. The paper presents the development and execution of a real-time intrusion detection system using an IoT platform and an ultrasonic sensor. The developed system has the provision of three different ranges of distances for different movements from the physical object. All the distances are continuously measured and displayed in the organic light-emitting diode. The processing unit of the system uses an ESP32 microcontroller which reads the sensor’s measured value and compares it to the specified threshold distance range. When the measured distance is less than the minimum threshold value, the light turns red, and the buzzer activates. If the value is more than the minimum distance but less than the maximum threshold, the light turns blue. Finally, if the value is more than the highest threshold value, at this point the distance is the most secure, and the light turns green, it means that the physical object is safe from intruders.