pH, EC and Water level sensor Integration

I’m looking to integrate a pH, EC and water level sensor directly into home assistant running on my raspberry pi 3B, to monitor and run some automations for a home growing system.

I’m relatively new to home assistant so I looked through the forums for some information on how to go about this but unfortunately couldn’t find a way to integrate these sensors directly into home assistant, with the closest solution using an additional micro controller and communicating with home assistant over mqtt (Which I’d like to avoid in preference of a simpler/cheaper design).

Is there a way in which I can integrate these sensors into home assistant via my pi and if so how and where can I look for the relevant code and hardware?