Introduction: Arduino RMS Meter Module
This is a small Arduino module for measuring TrueRMS voltage. The meter displays the rms voltage in mV with digits and an analog level scale.
The module is intended as a "build in" module for monitoring a signal.
Step 1: Specifications and Parts
- Bar-graph / Digital readout.
- Specifications: Vrms: 50mV -> 1000mV
- Freq: 20Hz – 20kHz
- Input Impedance: 50 kohm
Dimension: 30x30x30 mm – display frame 3D printed
Arduino sketch: 3794b / 46% - 141b / 28%
- ATtiny85 (DIL)
- TLE2071 (OpAmp)
Step 2: Circuit Diagram
The design is build with an input circuit for correct signal level for the Arduino.
This is designed by a virtual ground level of 2V5. This is needed for the analog input and correct signal measurement.
The op-amp also improve the input impedance. The overall gain is 0dB.
Step 3: Arduino Code
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2 years ago
Thanks for sharing :)