Prevention of the spread of disease is the most critical effort before the domino effect occurs. One way to prevent its spread is to practice social distancing. Prevention of the spread of covid-19 can be easier by doing Contact Tracing. Contact tracing is done to find out who is infected. This paper proposes an accurate and energy-efficient tracing system based on an android application by utilizing Bluetooth Low Energy (BLE) signals from smartphones to automatically detect possible contacts between users. Using BLE level signals, each app estimates its distance to its opponent. However, calculating the approximate distance with a BLE level signal cannot yield a sufficiently accurate number. Therefore, the prototype of the contact tracing system implements zoning based on the signal level. The results show that the Received Signal Strength Indicator (RSSI) threshold at one meter is accurate for tracing, provided that the devices share the same chipset. Moreover, it is pretty energy-efficient to be installed on a user’s Android smartphone because it only requires 14.17 mAh for 6 hours of operation or the equivalent of 2.14 mAh per hour.

Nowadays, wireless sensor networks (wsn) have many implementations in agriculture, animal husbandry, education, and many more. To support the lifetime of wsn nodes to achieve battery-saving protocol, we propose the head cluster method. This protocol will reduce the power consumption in data transmission by using the concept of head cluster and cluster member. In this method, communication using the cluster head is only carried out by the group head to save energy consumed. Based on the simulation results, the network lifetime with the cluster head method can be increased compared to a single hop.

Drive technology for mobile robots is currently developing very quickly, especially for the type of wheeled driven platform. The driving models such as Ackermann steering, DDMR, and Omni-wheel robots have been widely implemented as mobile robot platforms. However, to answer the challenges in the robot contest where the competition is getting tougher, research is needed on a mobile platform that is more efficient, faster, and more precise. In this research, the design and fabrication of a mobile robot platform with a swerve drive model will be carried out. Swerve drive has independent driving and steering at each wheel. This model can provide a higher speed and freedom of maneuver for the robot compared to the DDMR, Ackermann steering, and Omni wheel drive models. However, swerve drive requires a higher number of motors as well as a more complex control algorithm in regulating the speed of the wheel drive motor and the steering angle on each independent wheel to be further controlled simultaneously in moving the robot to the target position and orientation. In terms of the control system, a multi-level control will be made where the low-level control will regulate the speed of the wheel drive and its relative direction to the robot’s body. Meanwhile, high-level control will be used to coordinate the movement of each wheel so that the results can make the robot to move according to the given trajectory.