Voltmeter using Arduino Nano

Make a potential divider across the analog pin and the voltage you are checking. Resistance values are mentioned in the code as well.

Using an Arduino Board as a Multiprobe Voltmeter

Arduino based Automatic Measurement System that can measure voltage and current in the ranges: {-500mV... +500mV}, {-5V... +5V} (changeable)

pequeño código en arduino para crear un voltimetro que utiliza Aref para eliminar errores de lectura procedente de la fuente de alimentación para adaptarse y tomar una medida mas real

measuring voltage using attiny13 and attiny85

This project implements a voltmeter which measures DC voltage upto 50 volts. A 16*2 LCD display paired with arduino shows the reading of the voltmeter. The connection consists of a voltage divider circuit to measure such large voltages.

A clock made with an analog voltmeter controlled by an Arduino nano.

A simple Arduino-based digital voltmeter using a 16x2 I2C LCD display.

An Arduino-based clock which displays the date and time with voltmeters

Мониторинг наличия напряжения в электросети (опционально контроль температуры и влажности помещения)

Simple Voltmeter Clock using ESP8266

Voltmetr pro Arduino Uno

Code for Arduino with components scheme - speedometer (0-33km/h) + voltmeter (0-40 V)

C'est un projet qui consiste à mesurer les tensions.

The output voltage of the sensor is converted by ADC.

Open source firmware for DSN-VC288 3 digits volt amper meter

An Isolated design for a demo board using the Analog Devices ADE9078 3 phase AC wattmeter. Design allows both WYE (STAR) and Delta (TRIANGLE) distributions to be measured along with Blondel and non-Blondel measurement schemes. The project includes a SPI based Arduino style library.

Tiny Scope for Arduino