Week 6 (FYP 2)

           

                 For this week, I try to test my circuit use my old block diagram by using Op-Amp (Non-inverting), Voltage comparator (Switching  circuit) to amplify the output but it's failure because of many noise ad distortion on signal of the waveform when test using Oscilloscope. Then, I do my research to find the suitable Op-Amp to amplify the signal of sound. lastly, I found one useful webpage for my research that use Electret Microphone with Op-Amp OPA 334.  

Website: http://microcontrollershop.com/product_info.php?products_id=4535 

The website also include the schematic diagram shows as below:

Figure 1: Electret Microphone Board Schematic

               When I test the schematic circuit above it's most functioning with smooth output and I decide to use these Op-Amp OPA 334 as a amplifier compared to use the old method. The figure below shows the my new block diagram and new schematic diagram :

Figure 2: Block Diagram of Electronic Stethoscope

Figure 3 Schematic Diagram of Electronic Stethoscope

                The schematic diagram above explain detail about the block diagram and what the components use for this project and also how the flow process the project functioning. Firstly, condenser sensor receives the signal from the attached microphone stethoscope to the chest and then submitted to the operational amplifier (OPA334). After that, the Op-amp amplify the signal from the sensor before transfer data for create the program using Arduino software. Lastly, the reading of heart beat was display at the LCD.