10 University of Electronic Science Technology of China(UESTC) 8 Square waves(40 HZ)(Ultrasonic) Utrasonic Sensor GND VCC Echo Trig (20 us pulse) GPIO Capture the Time Duration of high-level voltage GPT MCF 5213 Real-Time Systems Lab10 Real-Time Systems Lab University of Electronic Science & Technology of China (UESTC) Utrasonic Sensor GND VCC Echo Trig (20 us pulse) GPIO GPT Capture the Time Duration of high-level voltage MCF 5213 8 Square waves (40 HZ) (Ultrasonic)