Toggle switch keyboard emulator

[55pilot]

Get rid of the resistor in parallel with the LED. I am not very optimistic, but just that one change might do it. Otherwise, decrease the resistor in series to 150 ohm.

If that does not work, increase the capacitor to 100uF and increase the resistor to 200 ohm

Report back with the results.

---55p

Edited to add: All the above changes are in addition to removing the parallel resistor.

 

[(*steve*)]

Get rid of the resistor in parallel with the LED.

That resistor ensures the LED in the optocoupler will turn off (more) sharply and not just get dimmer and dimmer...

It seems prudent to provide a sharper turn off since the keyboard controller is expecting a switch contact closure. I'd certainly agree with the larger capacitor. I am surprised that the keyboard controller is not filtering out any "bounce".

Is it possible that the keyboard is using hall effect switches? I know they exist, but it would probably be one hell of an expensive keyboard.