In this lesson I will show how to do echolocation on the Raspberry Pi with the HC-SR04 Ultrasonic Sensor, from your Sunfounder Raphael kit. We show step-by-step instructions, and show how to code up the unit. We then show to to initiate a ping from the sensor, and how to detect its return, and measure the time of flight of the ping. Future lessons, we will use this to measure distance.
