Hackaday: A Phased-Array Ultrasonic 3D Scanner From Scratch. [1]https://hackaday.com/2021/05/15/a-phased-array-ultrasonic-3d-scanner-from-scr atch/ References 1. https://hackaday.com/2021/05/15/a-phased-array-ultrasonic-3d-scanner-from-scratch/