If I understand correctly, I feel like OpenCV and computer vision is a huge overkill for something like that. Here are a few thoughts: 1. A microcontroller wit

If I understand correctly, I feel like OpenCV and computer vision is a huge overkill for something like that. Here are a few thoughts: 1. A microcontroller with a LoRa module and a motion sensor will get you a long way and it will consume little to no power. That said, you also need to make sure you have a device to either read the signal or someone in a radius of 4 to 6km is hosting a lorawan gateway. If not, I'm sure people will be grateful if you set up one yourself - to my mind it's worth it and I happen to be the only person that hosts one and covers my area of the city. Just make sure you don't enable any of the other gimmicks the microcontroller might come with - wifi, bluetooth or whatever. For instance I have a bunch of these [1] and they seem like they would do the trick for you if you pair them with a motion sensor. I need to warn you though, the documentation is appalling. 2. If you do wanna go CV - you can but it will never be low power and you will need to figure out some connectivity. If it's a raspberry pi or some other SBC with GPIO, you could of course hook up lora to it. As for the CV itself - opencv will get you there or you could train a very small yolo-like neural network - if you control the environment/lighting and they are static, you only need a handful of sample images to train it and you will get great accuracy. Like even something in the very low double digits will do the trick. Imo that would be overkill and your best bet is still the first option. [1] https://www.lilygo.cc/en-bg/products/lora3 https://www.lilygo.cc/en-bg/products/lora3