rumus

30-3.3 = 26.7K = 26700Ohm
Vo = VixR1/(R1+R2)
Vo = 30x3300/(26700+3300)
26700+3300 = 30000
30×3300 = 99000
99000/30000 = 3.3
Vo = 3.3V

24-3 = 27K = 27000Ohm
Vo = VixR1/(R1+R2)
Vo = 30x3000/(27000+3000)
27000+3000 = 30000
24x3000 = 72000
72000/30000 = 2.4
Vo = 2.4V

Volt
value = analogRead(voltageSensor);
vOUT = (1024x3)/1024.0
vOUT = 3
vIN = 3/(3000/(27000+3000))
27000+3000 = 30000
3000/30000 = 0.1
3/0.1 = 30
if (vIN < 0.09) {
    vIN = 0.0
}

vOUT = (1024x3.3)/1024.0
vOUT = 3.3
vIN = 3.3/(3300/(27000+3300))
27000+3300 = 30300
3300/30300 = 0.108910891
Pembulatan 2 angka 0.108910891 = 0.11
3.3/0.11 = 30

Vout
R1 = 22000
R2 = 3000
vOUT = (1024x3)/1024.0
vOUT = 3
vIN = 3/(3000/(22000+3000))
vIN = 25V

Vout = 25x(3000/(22000+3000))
Vout = 3V

R1 = 22000
R2 = 100000
R3 = 100000
R4 = 30000
vOUT = (1024x3)/1024.0
vOUT = 3
vIN = 3/(3000/(22000+100000+100000+3000))
vIN = 225V

Vout = 225x(3000/(22000+100000+100000+3000))
Vout = 3V

Amps
R1 = 220000
R2 = 10
Vaccross = (1024.0x3)/1024.0
Vaccross = 3
Iamp = (Vacrossx22000)/10
Iamp = (3x22000)/10
Iamp = 6600