Voltage Sensor Module 25V
π What this module is
The Voltage Sensor Module (0β25V) is a simple analog sensor used to measure DC voltage using microcontrollers like Arduino or ESP32.
π It does NOT directly measure high voltage
π It uses a voltage divider circuit to reduce voltage safelyβοΈ Working Principle
The module scales down input voltage using resistors
Converts:
0β25V input β 0β5V output
This output is read by Arduino analog pin
β‘οΈ Internally uses a resistor divider (30kΞ© + 7.5kΞ©)
βοΈ Key Specifications
Input Voltage Range: 0 β 25V DC
Output Voltage: 0 β 5V (safe for Arduino)
Resolution: ~0.00489V (10-bit ADC)
Output Type: Analog
Operating Voltage: 3.3Vβ5V
π Pinout
Input Side (High Voltage)
VCC / + β Positive voltage to measure
GND / - β Ground
Output Side (Microcontroller)
S (Signal) β Analog pin (A0 etc.)
+ β 5V / 3.3V
- β GND
π§ Formula to Calculate Voltage
Since voltage is divided by 5:
Vinput=VanalogΓ5V_{input} = V_{analog} \times 5Vinputβ=VanalogβΓ5
π Example:
If Arduino reads 2V, actual voltage = 10V
π‘ Applications
π Battery voltage monitoring
β‘ Power supply measurement
π Automotive voltage sensing
π Solar panel monitoring
π IoT energy systems
β οΈ Important Notes (Very Important)
β Do NOT exceed 25V input β may damage Arduino
β Measures only DC voltage (not AC)
β Cannot measure negative voltage
β οΈ For ESP32 (3.3V ADC): max measurable β 16.5V
π When to use this vs other sensors
| Sensor | Use Case |
|---|---|
| Voltage Sensor (25V) | Simple voltage measurement |
| INA219 / INA260 | Voltage + current + power |
| ZMPT101B | AC voltage measurement |
π Why it's useful
Very cheap & simple
No complex library needed
Perfect for beginners + quick projects
