Trying to help out a drive-in movie theatre. A huge issue for them is people turning their lights on during the movie (they don’t realize it). What we would like to do is mount a camera on their screen, facing the lot, and it to notify if headlights are detected. Tricky points is some kind of luminance threshold to trip it. And can’t be motion because there is always motion.
Special bonus if there is a way to report to Home Assistant so we can use it in automations etc.
Thanks in advance!
Wouldn’t a simple lux sensor (or more) do the job?
A simple automation could then be set up to send a notification if the predefined lux level is exceeded, but only during movie times
I’ve searched extensively for one but can’t find one. It’s too far away for zigbee or zwave. And it needs to be outdoor rated. LoRa I think is the only option? I tried YoLink but they don’t have a lux sensor. Do you know of anything?
Is the screen front or rear projection…? If it’s rear projection or there isn’t a lot of spill from the projector, it might be helpful to just add a few retroreflectors around the screen so there is a more apparent indication to the people in the car.
ESPHome is also an option. They seem to support loads of light sensors, and a waterproof housing should fix your outdoor rating issues.
There are also network-attached zigbee coordinators which should solve your distance issues with zigbee. Again, for the sensors, either a waterproof housing or just making sure your sensor is not in direct rain should satisfy your requirements.
Many small weather stations have lux sensors on them. Mine uses 433MHz (ISM band) so the range in an open field could be up to 150m.
This isn’t the exact one I have, but the same idea:
These units often call themselves “WiFi”, but come with a base unit display that connects to the sensor via 433MHz, and shows the relevant info. The communication to that base unit is what you can intercept and pipe into HA. The WiFi part is just for using their app, which you don’t need to bother with (if you can find one without the base altogether, save yourself some money and skip that part).
Reading the data would be done via a cheap USB dongle and antenna, using this project:
Getting the light sensor to face the vehicles could be a little wonky from a weather station though. I wonder if there are other devices using 433MHz that have light sensors…looking through that project a bit for light_lux shows there are many supported devices that have light sensors, such as this:
You might be able to modify this a bit to only use the light sensor, or reorient it at least.