https://www.youtube.com/watch?v=52M5GOIqqW0
This device sends an IR signal for a Canon camera and can be used as a remote and intervalometer. Should work with Canon cameras that have an IR receiver.
Or you can replace LED with a transistor and adapt the device and program to work with cameras that accept a stereo (3 pole) 2.5 mm jack plug.
Also, you can adapt the program to work with Nikon cameras too! Here is a link to a tutorial from adafruit. (I don't have a Nikon camera to test it ...)
https://learn.adafruit.com/ir-sensor/making-an-intervalometer
Useful links:
https://publiclab.org/notes/cfastie/02-28-2016/auto-eos-m
https://randomnerdtutorials.com/guide-for-oled-display-with-arduino/
This project partially inspired by Attiny85 + SSD1306 Canon DSLR IR timelapse remote