#06intermediate

Solar Voltage Meter

Measure voltage levels with an LED bar graph display

Watch the circuit build itself: components drop in, wires connect, and the output comes alive.

Components

Everything you need for this project.

10KΩ

2x 10KΩ resistors

4x LEDs (1 red, 1 yellow, 2 green)

220Ω

4x 220Ω resistors

1x Potentiometer

8x jumper wires

How It Works

Voltage dividers for measurement, ADC scaling and calibration, multi-LED bar graph display, and voltage range mapping.

InputPotentiometer (voltage)
ProcessingESP32-S3 reads ADC, maps to voltage, drives LED bar
Output4-LED bar graph fills

What You Build

Voltage divider from potentiometer to A1. Four LEDs on D1–D4 form a bar graph representing solar panel voltage levels.

African Context

Solar energy adoption is accelerating across Africa. Technicians need to measure panel output voltage, and this circuit teaches the fundamental measurement technique.

What You'll See

Turning the potentiometer fills the LED bar graph progressively. Display shows calculated voltage and digital bar graph.