CJMCU-103 Rotary Angle Sensor Potentiometer Module

What is CJMCU-103?

The CJMCU-103 is a rotary angle sensor module based on a 10k potentiometer used to measure the angular position of a rotating shaft.

It converts rotation into a variable analog voltage Acts as a position sensor

Commonly used in robotics, automation, and control systems

Working Principle

• Based on a rotary potentiometer (variable resistor)

• When the shaft rotates:

  • Resistance changes

  • Output voltage changes proportionally

   

Process:

• Rotate the shaft

• Internal wiper moves across resistive track

• Voltage at output pin changes

• Microcontroller reads analog value

Converts mechanical rotConfiguration

Typical 3-pin interface:

• VCC 3.3V 5V

• GND Ground

• OUT Analog output

Compatible with Arduino, ESP32, etc.

Output Behavior

• Output is analog voltage (0V to VCC)

• Rotation changes voltage linearly

Example:

• 0 0V

• Mid angle ~2.5V

• Max angle ~5V (if powered by 5V)

Requires ADC (Analog-to-Digital Converter)

Technical Specifications

• Operating Voltage: 3.3V 5V

• Resistance: 10k

• Rotation Range:

  • Electrical: 0 300

  • Mechanicaesistance Tolerance: 30%

  • Operating Temperature: -40C to +85C

  • Output Type: Analog voltage

  Internal Components

  • Murata SV01A103 potentiometer

  • MCP6002 op-amp buffer

  • RC low-pass filter (noise reduction)

  Key Features

  • Smooth and continuous rotation sensing

  • Analog output for precise control

  • Built-in filtering for stable signal

  • Compact and lightweight

  • Dust-proof design for reliability

  Applications

  • Robot arm position control

  • Steering angle measurement

  • Motor shaft position sensing

  • Volume/brightness control knobs

  • Industrial automation systems

  • l>

    Advantages

    • Simple and low-cost

    • High reliability (long life cycles)

    • Easy to interface

    • Smooth output without steps

    Limitations

    • Limited rotation (not 360 continuous)

    • Mechanical wear over time

    • Analog noise may require filtering

    • Lower precision compared to encoders

    Important Notes

    • Use analogRead() in Arduino

    • Avoid applying excessive force on shaft

    • Use stable power supply for accurate readings

    • Suitable for absolute position sensing, not rotation counting

    Summary

    The CJMCU-103 Rotary Angle Sensor is a:

    Potentiometer-based angle sensor Provides analog voltage output Measures shaft position up to ~30/li>

  • Control systems

  • Analog input projects