The other week my car (a 13 year old Lexus LS400) got scraped in the car park at work by some muppet who obviously just drove off. Damage is minimal – just some of their paintwork which rubbed off but one tiny area on my car where the paint had been taken off.
This got me thinking about using one of the spare Raspberry Pis and the spare camera module I have lying around to record what’s going on in that car park during the day. The camera would have to be inside my car as there’s nowhere with a view of the car park from our building at work.
Looking in my box of bits, I found a Pi Supply to manage the power and provide soft shutdown together with a HotPi to provide a real-time clock (it does a lot more than that, by the time I got it I had changed my mind on how I access my media centre Pi so it’s just been sitting there).
Initially, I was going to use a cheap Chinese buck-boost DC-DC regulator to get 5V from the 12V supply in the car. The board just didn’t work, sigh, and the lighter sockets in the car are only active when the ignition is on anyway. I might have an option to tap into the reading light circuits for the rear seats but I don’t really want to start pulling the car apart – I’m likely to do more damage than the wanker who hit it the other week.
That only really leaves a stand-alone solution. A good sized plastic box from a previous Proto-Pic order looked like it might make a decent enclosure:
The Pi is buried under the foam which also keeps the power pack in roughly the right place. The plastic on these boxes is really easy to cut with a craft knife so it came together quite quickly.
I’ve brought out two leads from the power pack, one it’s own charging lead so I don’t need to dismantle anything to charge it and the other is 5V 1A supply to the Pi Supply board. The nearest USB lead is the Pi power lead. The green/blue pair are used to signal the Pi to shutdown and then there’s the camera (obviously).
The battery pack is 5000mAh (allegedly). I’ve got it on test to see how long it lasts. If all goes well I’ll just need to switch it on and pop it on the rear parcel shelf when I get to work and do a quick shutdown when I leave. Charge the battery overnight, check the files on the USB stick and wipe it clean ready for the next day and it should be ready for the next time some prat who can’t drive does something stupid. Unless the pikeys smash my rear window and nick it, of course.