The code is to interface a DSC PC1500RK alarm keypad. It has 15 keys, 11 LEDs, and a Beeper that can be controlled. This code cycles through all the LEDs in a top-down fashion. The beeper is used ...

Modern, slim-line landscape keypad Enlarged keypad buttons 5 programmable function keys Input/Output terminal Fire, medical and panic keys. Available with English function keys. Adjustable backlight ...

12 or 24 hour clock display. Zone input connects detector to keypad to avoid separate wiring back to panel. 5 programmable one-touch function keys with 25 options. LED status indicators. Piezo buzzer ...

But that project only showed you how to interface the Arduino with the keypad — [Doug] went the ... on GitHub in case you also have a DSC 1550 alarm system. It’s a pretty slick hack, so ...