Many of the older Canon A series point & shoots can be highly controlled by use of a free software product called "CHDK" - Canon Hack Development Kit. The features provided add considerably to each camera's functionality.
These cameras are often available 2nd hand at low cost. Lists of suitable cameras are available.
CHDK is immensely capable - you can trigger a sequence of timed stills or video based on movement in selected area, set interval timers, set ISO and extract RAW files on cameras that do not offer the facilities usually & much more.
Start here CHDK Wiki and then
this garglabet search will provide ample extra.
SOME OF THE FEATURES: (from the Wiki)
Shutter-priority (Tv) exposure - via shutter value override feature
Aperture-priority (Av) exposure - via aperture value override feature
Shooting in RAW, with RAW Average, RAW Sum, and RAW Develop features
DNG (Digital Negative) in camera conversion, and USB download options
Bracketing -Tv, Av, ISO, and Focus bracketing, using scripts, or in continuous or custom timer modes
Live histogram (RGB, blended, luminance and for each RGB channel)
Zebra mode (a live view of over and under-exposed areas of your picture) for many cameras
Depth-of-field (DOF)-calculator, Hyperfocal-calculator with instant Hyperfocal and
Infinity focus-set, and more
RAW and Video space-remaining gauges with custom low-limit alerts
USB cable remote shutter release
Motion-detection trigger - automatically fires camera on motion detection. - Ability to capture lightning strikes.
Adjust Video quality and size (compression) adjustable while recording
Elimination of 1 Gig video-size limit (for most DIGIC II cameras)
Zoom during video function - for cameras without this feature
Shutter, Aperture, and ISO Overrides
Ultra-long shutter speeds - at least up to 64 seconds - and longer for supported
Ultra-fast shutter speeds - up to 1/10,000" and higher
High-speed Flash Sync at all speeds up to 1/64,000"
Custom, user-editable visible grids for framing, cropping, and alignment (not all cameras)
Fully customizable CHDK display, info placement, user colors, fonts in menus, etc.
Multi-language Interface - CHDK supports many languages
Custom CHDK User Menu - for instant recall of up to 10 favorite functions
Scripts execution - including intervalometer, motion detection, etc