# HCSR04設計原理 original design: https://www.robot-electronics.co.uk/htm/srf04tech.htm http://www.robot-electronics.co.uk/htm/srf05tech.htm analysis: http://www.pcserviceselectronics.co.uk/arduino/Ultrasonic/electronics.php http://www.pcserviceselectronics.co.uk/arduino/Ultrasonic/advanced.php https://www.davidpilling.com/wiki/index.php/HCSR04 innovation: https://uglyduck.vajn.icu/ep/archive/2014/01/Making_a_better_HC_SR04_Echo_Locator.html https://www.youtube.com/watch?v=VuzytIcSxwI https://www.hackster.io/graham_chow/spread-spectrum-phased-array-sonar-018e22 Sidelobes test(開角實驗): https://www.robot-electronics.co.uk/htm/reducing_sidelobes_of_srf10.htm ###### tags: `超音波研究`