By the time I got home it was a bit after 7:30 pm. I opened the garage door and parked the car, closing and locking the garage door. Grabbed the mail from the mailbox out front, and went up to the front door. The alarm system was still on, and there was no indication of anyone trying to break in. I had set up the alarm system so it would show a special alert code with the blinking of a green LED that was hidden in the eaves above the door. It was hidden pretty well, you had to stand in a specific part on the front porch and know where to look if you wanted to see it. The light pattern was normal, so I unlocked the front door and went inside to the control panel. I punched in my access code, and disabled the alarm, locking the door behind me.
My alarm system was pretty fancy. All the windows and doors were alarmed with proximity switches hidden in the window frames and the door jambs. The garage door also had proximity switches. They were all wired to the main control panel that was hidden behind a false panel in an inside closet in the hallway. All the doors and windows had at least two switches, with every switch having a separate wiring system.
I had modified the main control panel to log to a 64M RAM chip, using a short code value for each switch. The RAM chip had a battery backup in case of power failure, and could hold enough data for a couple of week's worth of information. A simple serial port on the control panel was an interface to a laptop so I could program the alarm system, or look at the log.
It was a bit of overkill for the stuff that I had in the house initially, but I had played with a few alarm systems when I was a teenager. I kept tweaking the alarm systems that I made then with new features, basically just because it was fun to make things all work together. My first one had a Z80 chip with a 4K RAM chip, and used switches arranged in 8-bit binary pattern to program the alarm system. When you have to enter a program with 8 patterns of 8 switches, you learn how to program quite efficiently, a skill that I used a lot later in my professional life.
In fact, the alarm system design I used now was more fancy than most you could get then. One of my neighbors ran an alarm company, and I showed it to him one day a few years ago. He really liked the design, and ultimately his company bought the rights to the design from me. Of course, I had a lawyer for the whole process, even though the neighbor was pretty honest and didn't try to screw me. They got exclusive license rights to the design, I retained ownership of the design and all future modifications, and got a royalty on every system they sold. And I also got a small piece of the company.
That "small piece of the company" turned out pretty well. The alarm company was eventually bought out by a nationwide alarm company, mainly because of my alarm system. I retained my interest/ownership in the alarm design through the buy-out (lawyers can be useful!). I continued to get royalties, and I also got a small pile of stock options in the big alarm company. (I can't tell you their name, due to confidentiality restrictions, but you see - or used to see before the Problem - their ads on television all the time.)
Anyhow, the royalties from the alarms, along with the profits from the stock, were quite nice through the years.
When I moved into my current house, I took the alarm system and modified it a bit more, then installed all the switches and alarms to it. (I'll admit it: it was the techno-dweeb in me,) Every once in a while, I'd get into a mood for playing around with it, so I'd add additional features, like the LED in the eaves of the front porch. And even though the electrical power at the house was pretty consistent and reliable, I set it up with an uninterruptable power supply just in case of a power failure.
Anyhow, the alarm system was quite complex, but it worked. I knew that if anyone tried to get in, I'd know about it. It was a pretty quiet neighborhood, though, not much traffic, sort of out of the way, so the only people who came back on the street were those that lived here, along with the mailman and paperboy and occasional delivery van.
I've got a similar alarm system here at the cabin that I installed after first finishing the cabin. Since I didn't live at the cabin full-time until after the Problem, the alarm system was needed to keep things secure. The cabin is in a pretty remote area. So I'm well-protected here with my alarm. And the "Smith & Wesson" backup system.