4 ms·

Used to be done with a literal diode.

• kps 7y ago
  Well, an optoisolator is a literal diode plus a literal transistor. I'm okay with that much hi tech.
• basilgohar 7y ago
  The funny thing is that LEDs (granted, not all types of diodes) can be used to read data as well as transmit it. Videos of such interfaces can be found on YouTube. So, they are not as one-way as some folks may think. https://youtu.be/aLP-OF4nesY https://youtu.be/aLP-OF4nesY
  • temac 7y ago
    Well it can not only be a LED that is supposed to be one-way, but the whole circuitry driving it. Likewise for the receptor. With some appropriate review of the physical design, you can have a reasonable expectation that the comm will be limited to one-way, with no way for arbitrary SW to modify the direction.
  • debatem1 7y ago
    Usually wasn't an LED. Just a normal diode.