Newbie....Need to control a transmission

Folks
To start with I am a newbie.

I need to replace an obsolete, unavailable transmission controller on a piece of earthmoving equipment.
The input is a momentary contact to increase the gear and a separate momentary contact to decrease the gear.
With a separate maintained contact for forward or reverse.

The output is it energize between 1 to 3 of 7 possible solenoids.

There also needs to be an adjustable time delay to allow the mechanical systems to smoothly shift without attempting to be in 2 gears at the same time.

I'm thinking of using relays to control the solenoids as each draws about 2 amps. Although if it works I may convert to using MOSFETs.

The inputs will need to be heavily debounced and the power supply filtered .

Mostly I need some help in getting started and some ideas on available libraries that I can leverage.

Thanks
Greg

I don't see any need for libraries. What you need is just basic digitalRead and digitalWrite and delay. That's about it.

And to draw out the state transition diagram. Given a mistake might damage mechanicals,
debug the system using LEDs in place of the solenoid drivers until you are happy its
sequencing correctly.