Hi, I am designing a project to get the status of the phone line and convert it to 8bit and send it to the com1 port on the computer, I found the almost part of the circuits in the internet (on hook off hook circuit ) (Dtmf detector circuit ) sprately and i want to connect this tow circuits together ,
I use hm9720 ic witch comptible with 8870 to detect the DTMF
and for (on\off hook) you can found it **broken link removed**