Buy Arduino DC Voltmeter with OLED | Measure 0-50V Student Projects in Lahore

COMPONENTS USED: • Arduino Uno/Nano (any board works) • SH1106 OLED Display (128x64 I2C) • 100kΩ Resistor (R1) • 10kΩ Resistor (R2) • Breadboard & Jumper Wires COMPLETE WIRING DETAILS: VOLTAGE DIVIDER CIRCUIT: Test Voltage Input (+) → 100kΩ Resistor → Arduino A0 Pin → 10kΩ Resistor → GND The junction between both resistors connects to A0 SH1106 OLED to ARDUINO: OLED VCC → Arduino 3.3V OLED GND → Arduino GND OLED SCL → Arduino A5 (Uno/Nano) OLED SDA → Arduino A4 (Uno/Nano) IMPORTANT: If using Arduino Mega, SCL=21, SDA=20 HOW THE VOLTAGE DIVIDER WORKS: Arduino reads 0-5V only. The divider scales down input voltage

Arduino DC Voltmeter with OLED | Measure 0-50V | Complete Wiring & Code

• Ratio = (R1 + R2)/R2 = (100k + 10k)/10k = 11
• Vin = Vout × 11
• Example: 5V input → A0 sees 0.454V → displays 5V
• Example: 50V input → A0 sees 4.54V → displays 50V

ARDUINO CODE: Donwload

REQUIRED LIBRARIES (Install via Library Manager): • Adafruit SH110X by Adafruit • Adafruit GFX Library by Adafruit TROUBLESHOOTING: If display shows 50V for 5V input → Your resistor ratio is wrong. Check if you used 1kΩ instead of 10kΩ for R2. If OLED doesn't work → Run I2C scanner. Common addresses: 0x3C or 0x3D If readings fluctuate → Add capacitor (100nF) from A0 to GND

https://www.youtube.com/watch?v=8rF9AxD6reQ