KnockLock by Group 12

KnockLock use piezo sensors which can vibrate and generate sound when a voltage is applied. Being arranged in a two by two array means KnockLock's brain can have four individual voltage readings to work with. This makes KnockLock far more secure than its competitors and allows you to set your favorite kncking rhythm! Principally, the microcontroller acts as a finite state machine (FSM). It takes in the voltage signal input from the piezoelectric sensors, and changes the digital output signals based on current and previous inputs. For more details, please refer to About Page.

This shows the structure of the project’s approach in achieving its purpose. As it is noted above three stages are declared (input, process and output). According to the input, relevant processing take place and the expected output is carried out. Input stage comprises of the piezoelectric sensors and a push button. Piezoelectric sensors detect a knock and the voltage generated by the sensors is amplified into the analogue inputs of the microcontroller. The microcontroller checks if the pattern knocked on the door matches a 4-digit password set by the user, one of the four LEDs light up when each digit is input correctly. When the correct password was entered, the microcontroller drives a voltage into the motor which represents the door being unlocked. Push button is used to access the “recording new pattern” function of the product. When the push button is pressed, microcontroller records the new pattern indicating the identification of a knock by flashing LED (Recording). Finally, microcontroller A is connected to microcontroller B using the method described in details in section 5.5.2.5. to display relevant messages on LCD screen.