Automation HAT input wiring/setting

Hi Folks–

I could really use some advice please. What I’m trying to accomplish is to have the HAT serve as a doorbell monitor which fields and screens deliveries via my intercom, permitting building access via a monitoring python script that acts accordingly.

My doorbell (a standard 3-button (talk, listen, buzz) / 4-wire intercom system) currently is routed through a Mimolite that is set up to detect when the doorbell rings sending a signal which is a pulsated low-voltage DC current. I want to have the Mimo trigger its own relay, and have the event be detected by one of the Hat’s inputs or ADC terminals. But thus far I’ve been unsuccessful. The monitoring script shows no variation using either input type.

Can someone please put me on the right path? Thank you.