I read this thread here about telephone monitoring circuit :
There is a circuit as shown(attached). How can i connect the output from the optocoupler to a microcontroller to detect whether there is ringing, off-hook, on-hook? the output has +12V supply connection whereas microcontroller detects +5V as high.
There is a circuit as shown(attached). How can i connect the output from the optocoupler to a microcontroller to detect whether there is ringing, off-hook, on-hook? the output has +12V supply connection whereas microcontroller detects +5V as high.