Voltage sensor module safely scales down DC voltages and converts them into readable analog signals. This article will discuss the voltage sensor module pinout details, specifications, internal schematic, Arduino interfacing, and common applications.

Catalog

Voltage Sensor Module Overview

The Voltage Sensor Module is a compact electronic module designed to measure DC voltage levels in a circuit and send the data safely to a microcontroller such as Arduino or ESP32. It is commonly used in low-voltage monitoring applications where direct measurement could damage the controller.

This module works using a built-in voltage divider, which scales down higher input voltages to a safe range for analog input pins. Most standard voltage sensor modules support input voltages up to 25V DC, making them suitable for battery systems, power supplies, and DIY electronics projects. It has simple pin layout and straightforward calibration.

Voltage Sensor Module Pinout Details

Voltage Sensor Module Specifications

Voltage Sensor Module Schematic Diagram

Voltage Sensor Module is built around a simple resistive voltage divider. It uses two fixed resistors, 30 kΩ (upper resistor) and 7.5 kΩ (lower resistor), connected in series between the input voltage (VCC) and ground (GND). This arrangement reduces the input voltage before it reaches the output pin, protecting the microcontroller from high voltages.

The junction between the two resistors is connected to the S (signal) pin, which outputs a scaled-down voltage. Because the resistor ratio is 5:1, the voltage at the S pin is always one-fifth of the input voltage. For example, a 25 V input will be reduced to 5 V at the output, which is safe for most Arduino analog input pins.

The lower end of the 7.5 kΩ resistor is tied to ground, ensuring a stable reference level for accurate measurement. Since the circuit contains only resistors and no active components, the module is passive, reliable, and easy to replicate using discrete parts if needed.

Working with Arduino

The image illustrates how a 0–25V DC Voltage Sensor Module is interfaced with an Arduino to measure the voltage of a DC source, such as a lithium battery. The positive terminal of the battery is connected to the VCC (0–25V) screw terminal of the voltage sensor module, while the negative terminal of the battery is connected to the GND screw terminal. This allows the module to safely sense the battery voltage without directly exposing the Arduino to high voltage.

On the output side of the module, the S (signal) pin is connected to one of the Arduino’s analog input pins. This pin carries a reduced voltage that represents the actual input voltage after passing through the module’s internal voltage divider. The GND pin of the sensor module is also connected to the Arduino GND, ensuring both devices share a common ground reference for accurate readings.

Once connected, the Arduino reads the analog signal and converts it into a digital value using its ADC. By applying a simple calculation in the code, the original input voltage can be accurately determined and used for battery monitoring or power management applications.

Voltage Sensor Module Applications

• Battery voltage monitoring in Arduino and microcontroller projects

• Power supply voltage measurement and supervision

• Solar panel and renewable energy system monitoring

• Battery management systems (BMS) for low-voltage batteries

• Overvoltage and undervoltage protection circuits

• DIY electronics and educational projects

• Robotics power monitoring and diagnostics

• Portable device power level indication

• Automotive low-voltage system testing (within 25V range)

• Embedded system power management and fault detection

Mechanical Dimensions

Conclusion

The Voltage Sensor Module provides a reliable way to measure DC voltages up to 25V using microcontrollers. Its internal resistive voltage divider design ensures safe operation by reducing higher input voltages to levels suitable for analog-to-digital conversion. With minimal wiring, no external components, and broad compatibility, it is well suited for battery monitoring, power management, and educational projects.