Ok it worked fine. i am struggling adding a V for volt behind number and maybe the greek lambda sign behind ads value.

u8g2.print((SupplyVoltage),"V"); this does not work.

u8g2.print(Lookup_Lambda(adcValue_UA), 2); what does the 2 stand for ?

I changed the Code so i can see the OnBoard Voltage instead of AFR (lambda is better). so i changed the code to look like this: //Calculate supply voltage. float SupplyVoltage = (((float)adcValue_UB / 1023 * 5) /10000) * 110000; //Output display data. u8g2.firstPage(); do { u8g2.drawXBMP(112, 4, 16,...