“Project: Ultrasonic 40khz modulation data communication (text transmission)
Parts list:
1) Ultrasonic transducer TX and RX (which i desoldered from a HC-SR04 module)
2) LM386 to amplify the received signal
3) LM393 for comparing the signal once amplified
4) Two Arduino Uno
5) 10K pot for the tunning
6) LED
7) 220 Omhs resistor
8) 100nF cap
9) 10K resistor”