TomTang

maybe you need one lcd that output 5v, and level converter, bi-direction 3v to 5v.

I don't think there are some issues in the schematic . or you test its input line and output line separately and measure it by osc Moderator edit: spam link removed

we can design many kinds of power for car, bulk and boost circuit. if you need any help, can you send us messages.

good idea! but i don't think you need to make every thing, you can buy standard parts and assemble them togerther, and make programe for the cleaner. i am one hardware engineer, maybe i can help you for it. Moderator edit: spam link removed