We use the Armed home option at night, we do remember to turn if off, because the digital calendar and lights in the kitchen won't turn on when it's activated.
Kids are always a good excuse to create silly and fun projects :D
There has been some reports here in Norway of alarm station employees sharing photos of nude people — caught on their own motion sensor cameras triggering the alarm…
I agree. The ZigBee protocol is encrypted, but a replay attack is probably still possible. Another advantage of a hard wired panel is that it's not dependent on the Zigbee network being operational, and could be operated on the backup battery for days.
I think many systems fall through if the threat model includes someone watching you and doing a replay attack. But I'd still prefer a hardwired panel TBD. It's just not very easy to retrofit, with hidden cables.
I think for people willing to put in the time — things have certainly become much easier. I started with AVR microcontrollers about 20 years ago, and couldn't even dream of accomplishing things I am easily able to to today. Raspberry Pi, Arduino; have changed the scene for sure.
But at the same time; maybe there is less inventive for someone to really dig into something, as you say: with soldering iron in hand. As so much is available as a product or service already.
My first "serious" soldering was a few PCB kits :)
There is no protection against voltage spikes on the inputs, there is just the pull-up resistor on the Raspberry Pi input. So this is a weak point. I did consider both EOL resistors and optoisolators when I first got started. But decided against it.
There are dedicated tamper inputs, which runs through the tamper switches in multiple devices before returning to the control cabinet. But EOL resistors would be a better and more secure option. I have thought about using something like an AVR microcontroller to read the voltage level and convert to something the Raspberry Pi could use. Maybe in the future.
I can always make changes in the future — thanks for your input :)
Maybe, but now I have one :) It has uses outside the security aspect as well; water alarm, door open notifications, home automations, it's fun and a great learning experience.
Seeing how many people have expensive monitored alarm systems here; I'm pretty happy with my educational and cheap setup :)
From the grid? See below. On the inputs? No, you're right.
> reliable power source
Not included in this post, because I'm not done with it yet, is the backup battery. The entire system runs on a 7.2Ah leaf-acid battery, which is connected to an electronic charger. So the alarm system power is isolated from the mains. I'm going to document this later in the series, when I'm all done :)
> compatibility with external centralized security systems protocols
I didn't really consider this, but it's easy to add if needed. Any examples?
I don't allow SSH into my home network — I only SSH into the Raspberry Pi to work on, or modify, the alarm system when I'm at home.
For remote access to the alarm system itself I use Home Assistant, which communicates the the Raspberry Pi on MQTT.
I'm, looking at cutting the power to the dish washer, and closing the main water valve in case of a water alarm. And there is a short siren burst every 10 seconds. But this is still very much a work in progress :)
I really like simple strip boards, as it allows me to make modifications after the fact. And I don't have the patience to wait for PCBs to arrive from China :p
Most sensors gets used on a daily basis — as they are part of other home automation, like motion activated lighting. I can put the system in "walk test" mode, which gives a verification sound every time a sensor is activated. And there is a siren test function. I try to do those about once a month.
> That’s the main use-case for such an alarm then.
I'd say so. As I said; we have good neighbors that would react to the alarm, and I get notified on my phone. But the pros are normally gone before anyone has time to react anyways :)
Agreed, I have no outdoor sensors — but will be installing an outdoor siren. It is delayed by one third of the trigger time, so with 60 seconds trigger time — the outdoor siren is delayed by 20 seconds.
Should we set off the alarm by accident, we then have 20 seconds to fix it, before all the neighbors are alerted.
Thank you :) Calling the police would be ideal, but then you have to involve an alarm company and use their system. They are expensive, and I wanted to build something myself.
1. Hm, maybe. If they were to arrive, they would have to call me — I could remotely disarm the system or give them the code.
2. Not sure, my closest neighbors are aware of the alarm system. No false alarms in 13 months I've been using the system.
3. I used to work as an alarm technician; you can't really prevent the pros breaking in, getting what they came for and getting out. But you can prevent someone spending a long time inside the house looking for things to steal.