week 5

Last Thursday (16/2/2012), I had a brief discussion with Mdm. Naza regarding my concern about my project. As I mention last week, the progress is out of the path so yeah, I am a liltle bit freak out!

Mdm Naza then suggested me to change the program from Assembly to Arduino UNO. Next, due to the changes I've made, I am going to use a piezo buzzer circuit to produce the sound frequency. (The decicion has been made, I'm going to change the circuit to more simpler!)
The circuit will be modified by the Arduino program. So, throughout the week, I've been doing some research on Arduino UNO as well as the buzzer circuit that will be used together with Arduino. If things goes well, I would like to add up other features like a switching(for patients to notify if they heard the sound) as well as the LCD display(to display the frequency value).

Arduino UNO

Theory of piezo buzzer

The piezo buzzer produces sound based on reverse of the piezoelectric effect. The generation of pressure variation or strain by the application of electric potential across a piezoelectric material is the underlying principle. These buzzers can be used alert a user of an event corresponding to a switching action, counter signal or sensor input. They are also used in alarm circuits. 

The buzzer produces a same noisy sound irrespective of the voltage variation applied to it. It consists of piezo crystals between two conductors. When a potential is applied across these crystals, they push on one conductor and pull on the other. This, push and pull action, results in a sound wave. Most buzzers produce sound in the range of 2 to 4 kHz.

The Red lead is connected to the Input and the Black lead is connected to Ground.