Calculators
Quick maths for every build
Work out resistor values, dividers, battery life and more. Each one uses the same formula as the Encyclopedia.
- Ohm's lawFind voltage, current or resistance from the other two.
- LED resistorPick the series resistor that keeps an LED safe.
- Voltage dividerScale a voltage down, for example a 12 V battery into an ESP32 pin.
- Battery lifeEstimate how long a sleeping, waking sensor node lasts.
- Ultrasonic distanceTurn an HC-SR04 echo time into distance and tank level.
- ADC reading to voltsConvert an analogRead() number into the real voltage.
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