Please move if there is a proper 'software' sub-forum.

Am after re-purposing a retired/orphan 'smart' phone with no service, for surveillance/wildlife/trail snapshot photo camera triggered by motion; help!

If you know of any application that can work, please advise.
No video, no service provider, no wifi. Just hang a retired 'smart' phone on a tree; later grab the phone hanging from the tree and look at pictures taken since last hung. Ignore supplying power to it.

This is not about a smart phone to communicate with a wifi wildlife camera at a trail to download images nor remote viewing. It is a walk-to-the-tree, look at the images taken, erase the unwanted. Hang it up again. Simple basics. Cannot find such ☹️

Is it too much to ask ? Decommissioned old phones filling drawers doing nothing when they have on-board the camera, the memory for saving, the brains to do it, the connectors/links to do it... Is there a web site dedicated for re-purposing these very featured useable 'junk' ?

Found many complex applications all aimed to the lazy press a wifi button to get video remotely. Plenty of surveillance camera applications too, all for video. No motion triggered photos ☹️

Do phones have motion-activation capabilities?

You might look for an app that takes pictures at regular intervals. Time-lapse with a large gap. Most phones nowadays have a feature that records several seconds of pictures with each shot, which improves odds of capturing something.

The software determines changes in the image to trigger capture; no need to have a motion sensor on the phone. As far as I know.

Settings can be changes in the image 'every xx seconds' , or recognize human, or vehicle...

14 hours ago, Externet said:

Am after re-purposing a retired/orphan 'smart' phone with no service, for surveillance/wildlife/trail snapshot photo camera triggered by motion; help!

I've never heard of a phone having a motion detector. They (some) have proximity sensors.

Google AI:

"Phone proximity sensors, located near the front camera, typically detect objects within a very short range of 10mm to 100mm (about 1 to 4 inches) to turn off the screen during calls. These infrared-based sensors generally use a "near" or "far" state, often with a 5cm maximum threshold to prevent accidental touches."

14 hours ago, Externet said:

Is it too much to ask ?

It depends on the model that was decommissioned.. ;)

What you need is called timelapse.

This is taking photos after a specified number of seconds or minutes in a loop.

The problem is that old phones have very weak batteries. And the phone cannot “go to sleep” because that would prevent it from taking pictures.

1,000 charging/discharging cycles of the phone = dead or dying battery.

1,000 daily charges = 3 years of phone life.

There is something called Termux, which is a Linux terminal with packages that you can download, or write a script yourself. Termux requires Android v6+.

Don't download Termux from Google Play, download it from F-Droid instead:

https://f-droid.org/packages/com.termux/

(2nd direct link to apk, you don't need F-Droid store app)

You also need Termux.API, which has a command for taking photos:

https://f-droid.org/packages/com.termux.api/

After installation, you need to grant them permissions.

The script for taking photos will look something like this:

#!/bin/bash
I=0
while true; do
	FILENAME=image_$I.jpg
	termux-camera-photo $FILENAME
	((I++))
done

ps. Add sleep 60 to get a one-minute delay between photos.

ps2. If you connect your phone to a power bank that is powered by a solar panel, it should work.

ps3. Start by writing down what model of phone it is.

Edited February 7Feb 7 by Sensei

17 hours ago, Externet said:

The software determines changes in the image to trigger capture; no need to have a motion sensor on the phone. As far as I know.

Such an application takes a photo, puts it in the buffer, takes another photo after a certain amount of time, and compares it with the previous version. It is simply subtracting R, G, B, of each pixel between the two versions of the photos. Then it calculates some threshold, above which it will be physically saved. You can write this yourself. You have a timelapse and you have a thousand photos from the whole day. Make yourself a script (or have ChatGPT do it).

If the threshold is set too low, it will detect natural changes in the time of day (sunset), which requires trial and error.

Several frames in a row should also be tested to increase reliability.

Thank you, gentlemen.

Orphan phones with no service I have are half a dozen+ Androids of several flavors all working good, have installed via router to some, "walkie talkie" ; electronics audio generation tools, and borescope applications, and tried 3 trail cameras applications that are complex to operate, some have face recognition, human recognition, car recognition... A.I. ... Like meant for geniuses, not for a dumb like me.

From the little I understand, the images are determined to be in motion when something like pixel "checksum" changes over a preset amount of time when sampling images and then the image is saved. Definitively not interested in time-lapse or burst method.

The solar fed external battery is exactly the implemented method. Leave that aside.

If you really want the spare phones characteristics, are Cricket U680AC; Coolpad 3632A; ZTE U304AA; Tracfone Z716BL; Cricket EC1002

The script portion written above is just hebrew to me. I can use it only in high-holding-hand baby-steps guidance mode.

Copy and paste this entire discussion into ChatGPT (you don't need to register or install an app), and you'll find out the rest. Just follow the instructions.

10 hours ago, Externet said:

Definitively not interested in time-lapse or burst method.

Timelapse takes photos, and then you have to filter them so that only those that are sufficiently different remain. So you have to compare the photos with each other.

Tell ChatGPT that you want a python script for comparing photos, and it will generate one for you.

10 hours ago, Externet said:

If you really want the spare phones characteristics, are Cricket U680AC; Coolpad 3632A; ZTE U304AA; Tracfone Z716BL; Cricket EC1002

Android 13. Ok. Termux will work OK. Just start from installing it from my previous links.