ReadTempAndHumidity

Liz Sensor Voltmeter

Voltage Divider Calculation for Wemos D1 Mini

To measure a higher voltage than 3.3V using the Wemos D1 Mini's ADC port, you can create a voltage divider with 47kΩ and 4.7kΩ resistors.

Voltage Divider Formula

$V_{out} = V_{in} \times \frac{R2}{(R1 + R2)}$

Given Values

• $R1 = 47kΩ$ (47000Ω)
• $R2 = 4.7kΩ$ (4700Ω)
• $V_{out} = 3.3V$ (ADC input maximum)

Calculate Maximum

$V_{in} = \frac{V_{out} \times (R1 + R2)}{R2}$

Plugging in the values:

$V_{in} = \frac{3.3V \times (47000Ω + 4700Ω)}{4700Ω}$

$V_{in} = 3.3V \times \frac{51700Ω}{4700Ω}$

$V_{in} \approx 36.3V$

Liz Sensor BME280