Measuring the underwater received power behavior for 433 mhz radio frequency based on different distance and depth for the development of an underwater wireless sensor network

Underwater wireless sensor network (UWSN) important to enhance the widely use of the application of the Internet of things (IoT) for underwater. Uses of the acoustics base of wave propagations are the best ways to establish the UWSN. But the unpracticality of the hardware due to the size and cost has limited the application of UWSN. Radio frequency (RF) wave propagation is the best way to overcome this situation. Low frequency of the RF wave is proven feasible and suitable for underwater communication. 433 MHz RF were chosen to measuring the underwater received power behavior between the transmitter node and receiver node based on different distance and depth. HC12 transceiver module was used as a transmitter and spectrum analyzer with the telescopic antenna was used as a receiver. The received power give a good reading when the transmitter note was at 0.5-meter depth with a maximum operating range within 12 meters from the receiver

An Early Drowning Detection System for Internet of Things (IoT) Applications

Drowning is the leading cause of injury or death for children and teenagers. Designing a drowning detection device by implementing an Internet of Thing (IoT) is needed. An Early Drowning Detection System (EDDS) is a system that gives an early alarm to the guardians (parents and lifeguard) if the detector triggered an abnormal heartbeat and the victims are submerged under the water for a long time. A microcontroller was used to control the signal received from a pulse sensor and time for the signal lost under the water before it is transmitted to the access point. The access point acts as a data forwarding to the database via an internet connection. Universal Asynchronous Receiver/Transmitter (UART) 433MHz radio frequency transceiver has been used to create the wireless communication between drowning detection device and monitoring hub. A triggered warning signal will be transmitted to the guardians via Android apps and web page