I found this calculator watch on aliexpress for under 3 Euros and intend to replace the PCB featuring an ARM chip, mainly to learn stuff. The LCD stays and I want to find out how to connect it.

https://www.youtube.com/watch?v=7ok6PN81VBU

This is the 3rd prototype of a seismometer made with an optical mouse, some PVC tubes, a laser, a small lens and an Arduino microcontroller. The aptly named Seis-mouse-meter is made with an intent to eventually detect and monitor elephant movements from a remote location. This was created on behalf of the Hathi March Bioseismics Team formed within the Frugal Science community (frugalscience.org) during Sep-Nov 2020.