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Hello everyone! I've just released my new firmware for the Cardputer: IMU Acoustic Analyzer.
This project transforms your device into a professional-grade acoustic scleroscope, allowing you to measure the structural hardness and elasticity of real-world surfaces.
⚠️ Important: How it works (and how to drop it)
This is a precision physical instrument. It does not come with a pre-filled encyclopedia of materials-you train it yourself.
By standing the Cardputer on its edge (SD card slot facing UP) and letting it naturally tip over and fall flat onto a table or floor, the internal IMU records the micro-impact. It calculates the material's properties and saves the acoustic profile. Later, it can instantly identify which surface you dropped it on.
The Drop Technique: Let it fall naturally. Do not apply downward force. Even a 1-degree tilt upon impact or hidden supports under a table will alter the acoustic stiffness!
Durability: Do not be afraid to use it. During development, I dropped my Cardputer over 1000 times using this exact edge-drop method (including onto hard tiles). Because it simply tips over from a standing position, the device easily survives without any damage.
✨ Technical Features
4-Dimensional DSP Engine: Polling the BMI270 at 1600Hz, the custom DSP doesn't just look at peak impact. It calculates MaxG (hardness), Ratio (elastic rebound), flight time, and AUC (Area Under Curve) to measure the true physical impulse and viscosity of the impact.
"Zero-Shot" Physical Insight: Even if a surface is not saved in your database, the analyzer evaluates the raw physics and gives you an instant diagnostic (e.g., Ultra-Hard | Elastic or Firm | Dampening).
🕹️ Controls
[ 1 ]: Start 3-Drop Measurement.
[ 2 ]: Add New Material (5-Drop Calibration).
[ 3 ]: Open Database List.
[ < / , ] & [ > / / ]: Navigate Database Pages (Left / Right).
[ 1 - 4 ]: Delete a specific material from the current Database page.
[ ESC / ` ]: Global Cancel / Return to Main Menu.
[ - / _ ] & [ = / + ]: Decrease / Increase system volume (emits an acoustic test click).
📥 Download
You can flash it right now via M5Burner - just search for IMU Acoustic Analyzer or Zeloksa.
You can also find the .bin release on GitHub:
🔗 https://github.com/Zeloksa/IMU-Acoustic-Analyzer
I would love to hear your feedback. Let me know what materials you scan and how your calibration profiles look!
