Best way to use Driveay alert output (Open Collector NPN)

Question

I'm learning as I go on this project.

I have a beam-break driveway alert that I would like to get the output from on a device like an Arduino or Raspberry Pi and need some guidance on the best direction to achieve what I need.

The output details from the alert receiver are:

• The Base Receiver may be interfaced with an alarm panel. The alarm panel maybe configured with connections for zone sharing, or single EOL resistor per zone input.
• All switched Outputs are ‘open-collector’ type.
• Definition: Open-collector outputs switch to ground when active. When not active they are in a high impedance state.
• Use 12V Relays with EOL Resistors when panel is wired for zone sharing (for isolation)
• Zone outputs are protected from inductive loads.

The plan is to implement a device to receive the driveway trigger and add a few functions in stages starting with playing an (wav type) amplified audio alert (rather than a somewhat quiet beep), communicate to a smart home device (likely Shelly) to turn on external lights for a set duration during certain hours, grab an image from a driveway camera and send an alert, add a second beam-break to determine direction based on order or zones triggered and then change alert behaviour accordingly, and lastly squark an external siren if the alarm is armed.

What's the best setup to use with these objectives in mind? I was assuming a small device like an Arduino or PI running some gear & code to receive and process the input (I am more competent at coding than electronics), or a USB device to interface into a PC.

Answer 1

You will be able to use an Arduino to read the open-collector output directly. Just enable the internal pull-up and remember that the pin it's attached to will read HIGH when the beam-break is not triggered and LOW when it is.

Your other questions belong in their own individual posts.

Answer 2

I would always use a relay to isolate connections to external things. I have just finished half of a similar thing. I needed to control the gate from my home automation. All the inputs to the gate controller encoded. So I used a raspberry pi with a relay board, wired to a remote (for the gate). Now I can open, close, partially-open and lock the gate on a time-based plan.

The second half is to detect if the gate is open. In my case, I can't use the supplied PIR as its output is encoded. So I may end up mounting another POE PIR to detect if there is a car.