Precision Audio Scope

A powerful, cross-platform real-time oscilloscope and digital frequency counter built with Python. This tool repurposes your computer's microphone input or AUX jack into a high-precision measurement instrument.

Overview

Traditional software oscilloscopes often struggle with stability and precision at very low frequencies. This project was developed to provide a reliable, laboratory-grade tool for visualizing waveforms and measuring frequencies with professional accuracy using standard PC hardware.

How it works:

You can connect an external signal source (like a Signal Generator) to your PC's Microphone Input using a standard AUX cable. The software captures the raw audio data and performs high-speed analysis to display the waveform and its exact frequency.

Key Features

• Laboratory-Grade Precision: Uses a specialized state-machine algorithm with 5% hysteresis and sub-sample linear interpolation to provide frequency readings accurate to 3 decimal places.

• Superior Stability: Optimized to provide rock-solid frequency counts even at very low ranges (1Hz - 10Hz) where other tools often flicker or fail.

• Raw Waveform Monitoring: Displays the unprocessed signal exactly as captured by the hardware ADC, ensuring zero artificial smoothing or distortion.

• Interactive Scaling: On-the-fly adjustment of time windows and voltage scales using keyboard shortcuts.

• Cross-Platform: Built on PyAudio, making it compatible with both Linux and Windows systems.

Technical Specifications

• Frequency Range: Best suited for 1 Hz to 5,000 Hz.

• Sample Rate: 48,000 Hz (Standard Lab Rate).

• Processing: 2.0-second sliding math window for maximum frequency resolution.

Installation

Prerequisites

• Python 3.6 or higher

• System libraries for audio (ALSA on Linux)

Setup

pip install numpy matplotlib pyaudio

How to Use

1. Connect your signal.

2. Run the application:

python Precision_Audio_Scope.py

Controls:

• Left/Right Arrows: Zoom Time (Change horizontal scale).

• Up/Down Arrows: Zoom Voltage (Change vertical sensitivity).

• 'T' Key: Toggle Visual Trigger (Stabilize the waveform).

Safety Warning

Ensure your input signal does not exceed 1.0V to 1.5V peak-to-peak. Never connect a power amplifier output directly to your microphone jack.

License

Distributed under the MIT License. See LICENSE for more information.