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17 Apr 2018, 15:35

Smart Bar (Bar Deadlift Chest) and Magnetic Door Lock Control System

The information of the two champion teams in Phase II is listed below:

Smart Bar (Bar Deadlift Chest) - winning design

Pak-Yeung CHAN, Ming-Chung LUK and Lok-Pang YUEN

Nowadays physical training to keep fit and stay healthy in fitness rooms is very popular. However, many users cannot use equipment in fitness rooms in proper and safe ways. According to the U.S. Consumer Product Safety Commission, there were 1,500 visits to the emergency room from gym fitness equipment related accidents and 50,000 visits from home fitness equipment related accidents in 2009. To address this problem, we developed a smart device called Smart Bar for bar deadlift chest (see Fig. 1 and 2).

Fig. 1 Bar deadlift chest (source:

The problem to lift a bar is to maintain the balance and a user may get hurt if the bar is not balanced. It is difficult for the user to know whether the bar is balanced or not. There are four components in Smart Bar: two ultrasonic sensors, two speakers, an LCD display and a microcontroller. When the user lifts a bar with the smart device, two ultrasonic sensors at the two ends detect the distance between the bar and the ground. If it is not balanced, the speakers generate a high-pitch sound to alert the user. If it is balanced, the speakers generate a low-pitch sound to inform the user. Moreover, the microcontroller acts as a timer and a counter to assist the user. It tells whether the frequency to lift the bar is correct and shows the whole sequence for the user to follow to finish the exercise properly.

Fig. 2 Smart Bar

The demo video of smartbar:

Magnetic Door Lock Control System - winning design

Wai-Yip LEE, Shu-Mei LAW and Yeung-Yik SIU

Magnetic Door Lock Control System is composed of an Arduino microcontroller and different electronic components. It is a smart door lock with higher security or efficiency. Fig. 1 shows the control system. The system has two power supplies: one is 5V power supply for Arduino Mega 2560 and other is 12V for the magnetic door lock. Moreover, it has a switch to turn off the power of the door lock within a few seconds after the lock is opened. There is a keypad in the system for users to key in a password. When the key ‘*’ is pressed, the microcontroller resets the input. When the key ‘#’ is pressed, it means it is the end of the input.

Fig. 1 Magnet door lock control system

The maximum number of users is 100. A password can be a combination of 0 to 9 and A to D and the total number of characters cannot be more than 20. There are two modes in the system: More Security Mode (MSM) provides higher security. Users are required to input their passwords and show their RFID cards to unlock; while More Efficient Model (MEM) provides higher efficiency. Users either input their passwords or show their RFID cards near to the reader to unlock. An online web page (see Fig. 2) is provided to support both modes and it has three functions: unlock, add a new user and change mode. Moreover, users can access this web page by knowing its WiFi SSID, password and subnet IP address.

Fig. 2 Online web page

The first demo video of Magnetic Door Lock Control System:

The second demo video of Magnetic Door Lock Control System:

Information on each team in Phase II is detailed on the links below:

Organizer "Microcontroller Application Design Contest (2016-17)" Department of Electronic and Information Engineering The Hong Kong Polytechnic University

17 Apr 2018, 15:35