Capturing data from a sefty sensor power line

[yamanoorsai]

I asked a similar question in this forum earlier and this question is somewhat related to my previous question. I am trying to use a garage door sensor in one of my projects. The garage door sensor consists of an IR transmitter + receiver. The receiver has a red LED that turns off whenever the IR beam is interrupted.

I am trying to make use of the receiver output in my project. I have attached an oscilloscope capture of the receiver output. It is a 330 Hz signal and it consists of peaks and "dips" as shown in the attached picture. The sensor is powered at 12V and this was captured across the power supply terminals (garage door sensors do not have separate sensor outputs).

The peaks are really small and I have no clue about detecting this signal using a microcontroller.  Using a potential divider circuit did not help. I was not able to use opamp as a difference amplifier either. What would be the ideal method of detecting this signal