Analog Voltage Sensor Module (0–3.3V compatible)

Description

An Analog Voltage Sensor Module (0–3.3V compatible) is a compact electronic sensor board designed to measure external DC voltages that might otherwise exceed a microcontroller’s safe input limits, scaling them down to fit within a $0\text{V}$ to $3.3\text{V}$ range for an Analog-to-Digital Converter (ADC).

Key Features & Specifications

• Operating Principle: Typically based on a simple resistor voltage divider network (often with a 5:1 or similar ratio depending on the input range) that steps down higher voltages safely.

• Input Voltage Range: Usually handles DC voltages up to $25\text{V}$ (or $16\text{V}$ depending on the module variant), scaling the output down.

• Output Voltage Range: $0\text{V}$ to $3.3\text{V}$, making it fully compatible with low-voltage 32-bit microcontrollers like the STM32 and ESP32.

• Interface: 3-pin or screw-terminal interface:

  • DC Input (+ / -): Connects to the external power source or battery you want to measure.

  • Signal (S): Outputs the scaled analog voltage to the microcontroller’s ADC pin.

  • GND: Common ground reference.

Common Applications

• Battery Monitoring: Tracking the voltage level of 9V, 12V, or Li-ion battery packs in mobile robotics or IoT devices.

• DC Power Supply Testing: Measuring adjustable bench supply outputs or solar panel voltage generation.

• Microcontroller Prototyping: Safe analog sensing in student labs without risking damage to 3.3V sensitive I/O pins.

Usage Tips

• ADC Calibration: Because the module uses a resistance divider, you must write a simple scaling formula in your STM32 firmware to map the raw ADC reading back to the actual real-world input voltage.

• Ground Reference: Always ensure the ground of the measured circuit and the ground of your STM32 development board are tied together to maintain an accurate voltage reference.