Regarding electronics, I did not worry too much:
The piloting of the mount will be entrusted to an Astro EQ, I had a brand new kit left in my boxes.
The intervalometer, meanwhile, will be made by disassembling and then integrating a remote control camera easily found on eBay.
However, I modified the Astro EQ firmware to add features :
* Intervalometer control (Snap port, already present)
* Emergency stop (already present, but which does not remain engaged, adding of a latch)
* Ability to reverse the hemisphere in Standalone mode
* Possibility to cut the DEC engine in Standalone mode (battery saving)
* Control of a relay by Snap port 2 of EQMod (typically to control the heating)
* Incremental polar finder brightness adjustment button
Since the intervalometer will be two centimeters lower in the case, buttons require, I made a Plexiglas glass, to "deport" the display. This one was polished in order with sandpaper, toothpaste, then flame, so that it becomes transparent.