No so long ago, around 2012 :), I was still using my Psion 3c + a short OPL program, to trigger my hacked time lapse camera over serial line. It worked quite reliably for years.
https://forums.4fips.com/viewtopic.php?t=717
Funnily enough, my next foray into coding (after OPL) would be scripting timelapses on my Canon PowerShot with CHDK [1] — wish I’d thought of doing it with a Psion though.