The report details the implementation of distance measurement system using the ultrasonic waves. As the human ear’s audible perception range is 20 Hz to 40 kHz, it is insensitive to ultrasonic waves, and hence the ultrasound waves can be used for applications in industries/vehicles without hindering human activity. They are widely used as range meters and proximity detectors in industries also it can be used in parking assistance system. The distance can be measured using pulse echo and phase measurement method. Here the pulse echo methods used. The measurement unit uses a continuous signal in the transmission frequency range of ultrasonic transducers. The signal is transmitted by an ultrasonic transducer, reflected by an obstacle and received by another transducer where the signal is detected. The time delay of the transmitted and the received signal corresponds to the distance between the system and the obstacle.
Our final project is to design and build a portable blood pressure monitor device that can measure a user’s blood pressures and heart rate through an inflatable hand cuff. The device is consisted of three main parts: external hardwares (such as cuff, motor, valve, and lcd), analog circuit, and microcontroller. The anolog circuit converts the pressure value inside the cuff into readable and usable analog waveforms. The MCU samples the waveforms and performs A/D convertion so that further calculations can be made. In addition, the MCU also controls the operation of the devices such as the button and lcd display. Since we have the word ‘portable’ in our title, for sure all of the components are put together in one package which allows a user to take it anywhere and perform a measurement whenever and wherever he/she wants. Read more