Engine Sound Analyzer:RPM Calc 1.4

This application provides a method for estimating the engine Revolutions Per Minute (RPM) based on the exhaust noise emitted by motorcycles or cars while idling. It is particularly beneficial for the maintenance of vehicles that lack a built-in tachometer, such as scooters.

The sound generated while idling encompasses a variety of elements, including engine explosions, crankshaft rotation, and noise from various mechanical components. The application utilizes a microphone to analyze the recorded sound across different frequencies and calculates the RPM based on the loudest frequency detected. It is important to note that measurement results may be influenced by external factors such as ambient noise, vehicle type, device used, and proximity to the sound source; therefore, results should be viewed as reference values. Additionally, accurate measurement may not be achievable depending on the specific vehicle model, RPM range, and microphone quality.

• Set the number of engine strokes and cylinders
• Initiate measurement by pressing "RUN" or "▷"
• Adjust the Gain and Threshold settings to ensure the peak value is above the Threshold line
• Select any peak using the "<" and ">" buttons
• Stop the measurement by pressing "□"

* Note that measurement will conclude once the count is exhausted. Users can extend measurement time by watching a promotional advertisement or by restarting.

Users should adhere to the following safety precautions:

• Refrain from using this application while driving due to the inherent risk of accidents.
• Avoid touching heat sources to prevent burns or damage to devices.
• Ensure that the vehicle or machine is secured adequately to prevent movement, which could result in unexpected accidents.

The developer's background in DIY motorcycle maintenance inspired the creation of this application. During various routine adjustments or repairs, such as determining proper idling height or addressing engine malfunctions, there was often uncertainty around optimal RPM settings. By leveraging Fourier transform techniques to analyze engine sounds quantitatively, this application aims to provide a clearer understanding of engine performance.

It is hoped that this application will serve as a valuable tool for enthusiasts around the globe.