In preparation for my final project this setup tests comunication using visible light between an LED and a phototransistor. For the communication protocol for my final project is it important to me that the comunciation be perceivable by humans as well as slow and non-simultaneous so that it resembles the back and forth between two humans in conversation.
Talking board - bright LED, swtich to turn blinking on/off
Listening board - photo transistor, two LEDs for feedback
Talking, Arduino code