I am working on a project where I have to determine the position of vibration or knock using multiple piezo sensors. I am using simple piezo discs and reading the voltage signals from the discs using Arduino Uno synced with Matlab. I have 4 such discs arranged at the corners of a square plate. I have different signals at different time stamps. I tried working with the speed of sound to calculate the position but the results are not what I thought would be. Can anyone help?