Nice idea on blinking the LEDs to increase the resolution of the 3 LED display.
I'm having second thoughts... I might just want to re-build the whole thing. I like blinkies and displays, so I bought a ST7565 graphics display ($17) to try out:
There should be no issues working with an Arduino. I have used 16x2 displays with Arduino chips before, but never a graphics version.
I think it might be pretty cool to have a graphic representation of an analog dial.
See, I always make things more complex. You are a lot further ahead of me... my wife just gave me orders that "her" RV projects (that I am to do) take priority over mine.
But I told her - honey, if we overfill the black water tank, you'll wish we did my project first.
So she told me to buy those Horst sensors - which are now back in stock at
www.rv-partsplus.com. If you can stand having a non-commercial package. Apparently Horst changed suppliers and they had a delay in printing the packaging, and they decided to ship them without the over-package for those that want them.
So looks like I am putting in Horst sensors at least temporarily so I can get the other projects done.
But I envision myself setting at the campground soon with a beer in one hand and a voltmeter in the other hand messing with the circuits. No reason I cannot do it whilst camping...