How to Use Voltage Sensor: Examples, Pinouts, and Specs

The Arduino Voltage Sensor is a device designed to measure the electrical potential difference between two points in a circuit. It provides an analog output that can be read by microcontrollers, such as the Arduino UNO, to monitor or control voltage levels in real-time. This sensor is widely used in applications such as battery monitoring, power supply regulation, and energy management systems.

• Battery voltage monitoring in renewable energy systems
• Power supply voltage regulation
• Overvoltage and undervoltage protection systems
• Real-time voltage monitoring in IoT devices
• Educational projects and prototyping with Arduino boards

The Arduino Voltage Sensor is a simple yet effective tool for measuring DC voltages. Below are its key technical details:

The Voltage Sensor has a simple pinout, as shown in the table below:

1. Connect the Power Supply:

   • Connect the VCC pin to the 5V or 3.3V output of your Arduino board.
   • Connect the GND pin to the ground of your Arduino board.

2. Connect the Voltage to Be Measured:

   • Connect the positive terminal of the voltage source to the VIN+ pin.
   • Connect the negative terminal of the voltage source to the VIN- pin (or ground).

3. Connect the Output to the Arduino:

   • Connect the OUT pin to one of the analog input pins (e.g., A0) on the Arduino.

4. Write the Code:

   • Use the Arduino IDE to write a program that reads the analog voltage from the sensor and converts it to the actual input voltage using the scaling factor.

• Voltage Range: Ensure the input voltage does not exceed the sensor's maximum rating of 25V DC to avoid damage.
• Scaling Factor: The sensor typically uses a voltage divider circuit with a scaling factor of 5:1. This means the output voltage is 1/5th of the input voltage.
• Calibration: For precise measurements, calibrate the sensor using a known voltage source and adjust the scaling factor in your code if necessary.
• Noise Reduction: Use decoupling capacitors or filters if the input voltage is noisy.

// Arduino Voltage Sensor Example Code
// This code reads the analog output of the voltage sensor and calculates
// the input voltage based on the scaling factor (5:1).

const int sensorPin = A0; // Analog pin connected to the sensor's OUT pin
const float scalingFactor = 5.0; // Voltage divider scaling factor
const float referenceVoltage = 5.0; // Arduino reference voltage (5V for most boards)

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud
}

void loop() {
  int sensorValue = analogRead(sensorPin); // Read the analog value (0-1023)
  float sensorVoltage = (sensorValue / 1023.0) * referenceVoltage; 
  // Convert the analog value to voltage
  
  float inputVoltage = sensorVoltage * scalingFactor; 
  // Calculate the actual input voltage
  
  Serial.print("Input Voltage: ");
  Serial.print(inputVoltage);
  Serial.println(" V"); // Print the input voltage to the Serial Monitor
  
  delay(1000); // Wait for 1 second before the next reading
}

1. No Output or Incorrect Readings:

   • Cause: Incorrect wiring or loose connections.
   • Solution: Double-check all connections, especially the VIN+ and VIN- pins.

2. Output Voltage Exceeds 5V:

   • Cause: Input voltage exceeds the sensor's maximum range.
   • Solution: Ensure the input voltage is within the 0-25V range.

3. Inconsistent or Noisy Readings:

   • Cause: Electrical noise or interference.
   • Solution: Add a decoupling capacitor (e.g., 0.1µF) across the VIN+ and VIN- pins.

4. Serial Monitor Shows Incorrect Values:

   • Cause: Incorrect scaling factor or reference voltage in the code.
   • Solution: Verify the scaling factor (5:1) and ensure the Arduino's reference voltage matches the code.

Q1: Can this sensor measure AC voltage?
A1: No, this sensor is designed for DC voltage measurement only. Measuring AC voltage may damage the sensor.

Q2: Can I use this sensor with a 3.3V Arduino board?
A2: Yes, the sensor is compatible with 3.3V systems, but ensure the output voltage does not exceed the ADC input range of the board.

Q3: How do I extend the voltage measurement range beyond 25V?
A3: You can modify the voltage divider circuit on the sensor to increase the scaling factor, but this requires advanced knowledge of electronics.

Q4: Is the sensor safe for high-current circuits?
A4: The sensor is designed for low-current applications. For high-current circuits, use appropriate isolation techniques, such as optocouplers or transformers.