Managed to find a couple of hours this afternoon so into the garage I went.
I’d written the code for the microcontroller this morning – I really have kept it very simple but I’ll test it before posting it here and sticking it on GitHub. I think “simple” should work but I’ll be able to see how it does in the real world tomorrow. Time for some real work 😆
First up, I had to pop a new double socket up in the garage – there’s a need for one on the car’s battery side anyway, that side is not accessible when the car is in so less danger of treading on the sensor and there’s just more room. It was a simple decision.
Secondly, I needed to run a live from the lighting junction box and return switched live from the relay. Nothing special there then.
After a bit of drilling and wire pulling I ended up with this:
Here’s a close-up of the relay:
And some “context”:
All I need to do now is pop the microcontroller in the black box, run 3 wires to an HC SR-04 ultrasonic sensor on the floor and power the lot with a USB wall-wart. I’ve popped the cover plate over the relay and tested it with a 9V battery – it works just fine. I do like this solid-state stuff, you can switch it on with as little as 3V and you don’t have to fanny around with diodes – what’s not to like?
So, just a bit of low voltage “wiring” to do and this will be finished tomorrow 🙂