Building own hardware and firmware

Hello,

I need to design and develop my own hardware and firmware for Water management system in my home.
I am already using plenty of smart devices from Sonoff, Shelly, Tapo, TATA EZ, Smart life etc. I used there apps too.
But I am not able to build a ecosystem with one brand. Hardware and Software are also no so reliable.

I have good understanding of Electronics hardware and firmware development.
Now I have decided my own hardware development.
I am starting with a water level management system.

I decided to use ESP32-S3-DevKitC-1-N32R8V hardware. Its wifi capabilities convinced me.
I will use the best powersupply known to me from RECOM which can work even with 525V AC mains. My country has lot of fluctuations in AC mains.

I have two water pump motors which are rated for lesser than 5HP. I will use standard contactors from Schneider or similar.
I will drive their 230V coils with good quality relays and snubber circuits.
I have one Water storage tank in Underground and another as Over Head storage tank.
One motor is used to fill the UG tank by Ground water. Another motor is used to fill the water in OH tank.

I will use pressure sensors located inside the tanks to know water levels. I will use read switches too for redundancy.
I will interface a OLED Graphics display locally.
I will use a local Real Time Clock to log the events with time stamp. Internet connection is not so reliable in my country.
I will implement reliable voltage and current measurements for both the motors.
I will develop the hardware and firmware with my logic and calculations.

I understood that eWelink cube can locally run the server and customized App development is also possible.
Please let me know how to start the firmware development and App development for my customized application with eWelink Cube.

Thank you, Anesh S.

WoW! That will be tons of work!

Far from i know, lots of SONOFF devices can be flashed with firmwares that ESPhome developed and released, and for the iHost, i have seen some topics posted in this forum that some developers/contributers have discussions and try outs, Reflash your iHost with your own Linux distribution,
HAOS on Sonoff iHost · darkxst/ha-operating-system Wiki · GitHub, but i don’t think there’s detailed guidelines for how to develop a firmware for iHost, but eWeLink CUBE make the API opened on the official website for developers to create add-ons for their own.

Use home Assistant