From a hobbyist perspective, making something equivalent using a Raspberry Pi might be more fun, but just putting an old Android phone on a table and starting the app is so much easier.
The fact that an app so “obvious” is only now available, after 10+ years since we’ve had smartphones, makes me hopeful that there are still many cool things to build for mobile, even for older hardware.
I used to have such an app installed on an old first gen Nexus 7 tablet, whose dock was an angled landscape one. The app could detect sound, light changes, movement, and persist a record accordingly. At night it could switch to a high gain mode and/or make use of the screen as a light source. Alternatively it could livestream. And display a clock as camouflage. Can't remember the app name.
Use case? Monitor the cat who had the habit of being ill when I was away. Turns out neighbors made some strange noise that was too stressing to the poor guy.
Back in the days my friend had a motion detector (which just compared with previous input) on his webcam which would write the pictures which were served over Apache. He'd use this to figure out who entered his room (attic), and what they did there. Until one day his mother cleaned his room, the camera got pointed upward to the top window, and it was weirdly cloudy with clear sky in between. That day his harddisk got full.
Looking at the input devices for data:
Accelerometer: phone’s motion and vibration
Camera: motion in the phone’s visible surroundings from front or back camera
Microphone: noises in the enviroment
Light: change in light from ambient light sensor
Power: detect device being unplugged or power loss
This is a bit more advanced. It can warn when it loses function, power, or is unplugged. It can also be self-aware that its being moved or touched.
A Raspberry Pi can have a camera module and one can easily script the power loss capacity. You can plug in a microphone on the USB. Light sensor is sortof within the camera, just requires constant stream. Accelerometer is just a bonus on top of camera. You'd see the device moved via camera as well.
I see a few problems running this in a hotel room: its gonna need 24/7 connection. WiFi captive portals (common in hotels) usually time out after a while so you might prefer a SIM card, or either. Both would require something like a VPN or SNT. The data shouldn't be that much. Problem is, what if these networks aren't available? The power is essentially paid for, and not that much, but running this 24/7 is going to have impact on the battery life of your phone.
For me, this would be useful for another reason: cause we got a paid cat caretaker when we're not around.
I saw it can give you notifications over Signal. Does anyone have any info about how it sends messages without a phone number? I thought you need a phonenumber to have an account.
If I can send messages without a number then I'd like to try to add some feature to my VPS so that it sends me status updates :) Can you imagine getting a notifications when a build was done or sometching like that? It'd be really handy
It is, but without reproducible builds one doesn't know for certain that the available source is the running source.
I trust the Guardian Project not to insert backdoors, though. And I'm sure that the binary will be disassembled by some dedicated folks, for just this reason. Trust, but verify.
Yeah, but there's an enormous difference between closed source and "the very first public beta doesn't have a reproducible build system". Intent matters, you know.
Nice. But I'm sure there must be at least 4-5 such apps that were made, but never got much traction. I have seen apps that monitor surroundings using the camera, but someone must have combined all sensor data before as well.
As a digital nomad who's always on the road, I also have a backup Android phone in my backpack at all times in case I lose my primary phone. Can never be too careful these days.
That pdf does not address the case of (hidden) recording devices placed in the home by the homeowner. As a hypothetical - if two robbers are caught in conversation while in my home, do I first need their consent to record them (as even in the one party rules I would not be a party to the conversation)?
In your home, it might or might not be different, but either way, if you don't record audio, I think that you should be ok (I am not an attorney but I have never heard of a law preventing security video recordings containing only images, unless it is an invasion of privacy like in a bathroom or something similar).
From a hobbyist perspective, making something equivalent using a Raspberry Pi might be more fun, but just putting an old Android phone on a table and starting the app is so much easier.
The fact that an app so “obvious” is only now available, after 10+ years since we’ve had smartphones, makes me hopeful that there are still many cool things to build for mobile, even for older hardware.