Battery indicator

I have a scetch about a battery indicator to use on a arduino nano, it’s a demo version and I would like to have it tranfered in a working version
to measure the voltage of my accu like those are showen at a GSM

I have another sketch which wil measure voltage and I like to have those two combinent

I want to use the display in my modelbuilding truck !:14.5

The display is a oled 1306 0.96 inch 126 x 64

who could help me

swiftrapid

accu_spanning_meten_via_arduino_nano.ino (1.06 KB)

and the scetch for the indicator

Battery_Indicator.ino (8.89 KB)