Reverse engineering alarm keypad protocol

Question

I'm trying to reverse engineer the protocol that an old home alarm system uses to communicate with the keypads. Connected via 4 wires:

• GND
• 13.2V
• DATA
• CLOCK

I've managed to connect the wires to a logic analyser. Here's a snapshot of a periodic data packet that it sends:

(Top is CLOCK and bottom is DATA)

Based on observation of the packets it appears that the first part (slower clock) is the keypad sending data to the panel and the second part is the panel reporting status (sending data to keypad).

Does this protocol look like anything standard? I've tried different analysers in the Saleae Logic software, but nothing seems to output anything meaningful.

UPDATE:

I've disconnected keypad's data and clock wires and can see that the clock and the data is generated by the panel (the output is the same as on the above screenshot).

Here's what the signal looks like on large time scale:

Answer 1

I pressed the keypad buttons, observing light indicators on the keypad and capturing the signal using Saleae Logic software. It turned out that the protocol is dead simple: first part is a binary code for each button (8 bits) and second part is one bit per zone, light indicator and beep signal (16 bits).

I wrote a new ESPHome component to interface with the panel, so I can see the status and control the buttons.