Open2022/04/10にコメント追加2ソナーは作れるのか末廣尚義2022/04/10https://hackaday.io/project/174731-diy-echosounder 末廣尚義2022/04/10https://www.quora.com/What-basic-components-are-needed-to-make-a-DIY-sonar-sensor-in-order-to-measure-a-depth-of-a-river-up-to-30-metres
末廣尚義2022/04/10https://www.quora.com/What-basic-components-are-needed-to-make-a-DIY-sonar-sensor-in-order-to-measure-a-depth-of-a-river-up-to-30-metres