The Voltage Sensor DC 0-25V Module is designed to measure DC voltages between 0 and 25V. It is commonly used with microcontroller platforms like Arduino to safely measure higher voltages by stepping them down to a range that can be read by the microcontroller's analog-to-digital converter (ADC).

Specifications:

• Input Voltage Range: 0V to 25V DC
• Output Voltage Range: 0V to 5V (output to the analog pin of Arduino)
• Voltage Divider Ratio: 5:1 (the input voltage is divided by 5)
• Analog Input Compatibility: Works with Arduino, ESP8266, ESP32, and other 5V/3.3V compatible devices.
• Measurement Accuracy: +/- 1%
• Maximum Input Voltage: 25V DC (do not exceed this limit)
• Operating Temperature: -40°C to 85°C

Features:

1. Voltage Divider Circuit: The module contains a voltage divider that steps down the input voltage by a factor of 5. This allows the Arduino to measure higher voltages while keeping the input voltage on its ADC pin within the safe 0-5V range.

2. Simple Design: It has a very straightforward design with two screw terminals for connecting the voltage to be measured and a pin header for connecting to the microcontroller.

3. High Precision: The resistor values used in the voltage divider are carefully selected for precision voltage measurement with minimal error.

Pinout:

• VCC (+): Connect this pin to the positive terminal of the voltage source you want to measure (up to 25V DC).
• GND (-): Connect this pin to the ground terminal of the voltage source.
• S (Signal Output): This is the analog signal output pin that you connect to an analog input pin on the Arduino (e.g., A0).
• GND (-): Connect to the Arduino's GND to complete the circuit.

Applications:

• Battery voltage monitoring (e.g., 12V battery systems)
• Power supply voltage measurement
• Monitoring and regulating solar power systems
• General voltage measurement in electronics projects

Step-by-Step Guide to Interfacing the Voltage Sensor DC 0-25V Module with Arduino UNO:

Components Needed:

• Arduino UNO
• Voltage Sensor DC 0-25V Module
• Jumper wires
• Power source (e.g., a 9V battery or any other DC source for testing)

Pinout of Voltage Sensor:

• VCC / +: Input voltage (connect to the positive terminal of the voltage source you want to measure)
• GND / -: Ground of the voltage source
• S (Signal): Voltage signal output to Arduino (connected to an analog input pin like A0)
• - (GND): Ground pin (connect to Arduino's GND)

Step 1: Circuit Connections

• Signal Pin (S): Connect this pin to A0 (analog pin) of Arduino.
• GND (-): Connect this pin to GND on the Arduino.
• VCC (+): Connect to the positive terminal of the voltage source you are measuring.
• GND (-): Connect to the ground of the voltage source you are measuring.

Step 2: Write Code to Read Voltage

Once you've set up the connections, you can upload the following code to the Arduino to read the voltage.

Arduino Code for Reading Voltage:

// Define the analog pin where the sensor is connected
const int sensorPin = A0;

// Define the reference voltage of the Arduino (5V or 3.3V)
const float referenceVoltage = 5.0;  // This is the default for most Arduino boards

// The sensor divides the input voltage by 5, so the scaling factor is 5
const float voltageDividerFactor = 5.0;

void setup() {
  // Start serial communication to display results
  Serial.begin(9600);
}

void loop() {
  // Read the analog input value from the sensor (range: 0-1023)
  int sensorValue = analogRead(sensorPin);
  
  // Convert the analog reading (0-1023) to a voltage (0-5V)
  float sensorVoltage = (sensorValue / 1023.0) * referenceVoltage;
  
  // Multiply by the voltage divider factor to get the actual voltage being measured
  float actualVoltage = sensorVoltage * voltageDividerFactor;

  // Display the result in the Serial Monitor
  Serial.print("Measured Voltage: ");
  Serial.print(actualVoltage);
  Serial.println(" V");
  
  // Delay between readings
  delay(1000);
}

Step 3: Upload the Code

1. Open the Arduino IDE.
2. Copy and paste the above code into the IDE.
3. Connect the Arduino UNO to your computer using a USB cable.
4. Select the correct board and COM port from the Tools menu.
5. Upload the code to the Arduino.

Step 4: View the Output

• Open the Serial Monitor (Tools > Serial Monitor) in the Arduino IDE to see the measured voltage.
• The Arduino will continuously display the voltage being measured by the sensor.

Explanation:

• The analogRead() function reads the voltage from the sensor pin and returns a value between 0 and 1023, which corresponds to a range of 0 to 5V.
• We multiply the analog value by (referenceVoltage / 1023.0) to get the actual voltage at the sensor’s output pin.
• Since the sensor uses a voltage divider that divides the input voltage by 5, we multiply the result by 5 to get the real voltage of the measured source.

Precautions:

• Ensure that the input voltage to the voltage sensor does not exceed 25V, as this is the sensor's maximum rating.
• Always double-check your connections to avoid damaging the sensor or Arduino.