Hi, every electronics needs a multimeter, you can buy it or make it
yourself at home. Today I will show you how to make a multimeter with arduino nano and an oled display at home.

Functions:

Voltmeter 0 to 25 Volt!!!!!
Analog Read Value
Voltage Drop Diode
Continuity circuit
Capacitor Measurement
Signal PWM Generator

Step 1: Voltmeter 0 to 25 Volt!!!!!

Analog pins can measure a voltage not exceeding the supply voltage, but
you can increase the measured voltage by using a voltage divider. I used 7.5K and 30K ohms resistors, With a 5 volt microcontroller supply voltage (NOT ARDUINO, Arduino has a voltage stabilizer connected to the Vin pin) maximum voltage we can connect 25 volts. LINK TO CALCULATOR VOLTAGE DIVIDER