Accelerometer-based angle measurement system with application in hospital bed

This paper presented a design of angle measurement system using accelerometer and Arduino. The main components consist of 2 parts, ADXL33S Accelerometer IC chip and Arduino microcontroller. The function of ADXL335 Accelerometer is to perform an AC amplification, Demodulation unit, and output amp. The Arduino serves as signal amplification, analog to digital converter, low pass filter, isolator and SPI. SPI is served as an interfacing unit with the display. The LCD displays not only the angle but also the alarm system of angle measurement which is important for indicate the condition of patient bed. The results show an accuracy of the proposed system more than 80% of the angles. The results are very promising.