4 layers85.6 × 54 mm Sound spectrum v1, the printed circuit board in 3D

Sound spectrum v1

STM32-powered board to analyze sound from MEMS microphone

Size: 85.6 × 54 mm
Copper layers: 4
Thickness: 1.6 mm
Parts: 40
Nets: 49
Pads: 186
Tracks, vias: 410, 74
Pours: 1
Routed: Yes
KiCad: KiCad 9.0 (file 20241229)
Created: 15 Jan 2026
Updated: 2 Jun 2026

Overview

Sound spectrum v1 is an open-source printed circuit board by path321, from the path321/sound_spectrum_mcu repository on GitHub, published under the MIT licence. It is a 4-layer board of 85.6 × 54 mm with 40 parts on 49 nets, routed with 410 tracks and 74 vias.

It is built around the ICS-43432, AP2112K-3.3 and USBLC6-2SC6, with the ABMM2-24.000MHZ-E2-T among its other parts. Its parts include 16 capacitors, 6 resistors, 5 ICs, 3 connectors and 2 diodes. It belongs with the audio and music and sensors and measurement boards and the STM32 boards of this library.

Main components

README

README.md

Sound Analyzer

STM32-powered board for analyzing sound input from MEMS microphones, designed as an open-source, hands-on introduction to DSP on ARM Cortex-M4 processors.

device_image

About the Project
Project Status
Getting Started
How to get help
License

About the Project

It uses the CMSIS-DSP library to handle computationally intensive tasks, while a companion PyQt-based Python script is used for plotting frequency-domain data data from PCB to host PC.

The goal is to demonstrate the full pipeline of audio signal acquisition and transformation, from raw time-domain data to frequency-domain analysis

The PCB intentionally exposes additional unused pins, allowing users to extend functionality and experiment beyond the core features

1kHz sine 1khz

Front	Back

Project Status

In progress, working version availabe in main branch

Full STM32CubeIDE project is hosted here, with .elf and .bin files ready inside code/sound_analyzer_v1/Debug folder

As for python script, both source plot_graph.py and executable plot_graph.exe are available, with executable tested only for Windows platform

Getting Started

For application usage, no extra programm shall be installed , other than downloading the executable plot_graph.exe

For developer usage, STM32CubeIDE + STM32CubeMX shall be installed, as described here

In addition, Python >=3.9 shall be installed from here, with the following Python libraries also installed :

Numpy
PySide6
pyqtgraph
Pyserial

PCB files are located on pcb/ folder, while device files can be found on code/sound_analyzer_v1/ and plot files on code/plot_graph/

Getting the Source

This project is hosted on GitHub. You can clone this project directly using this command:

text

https://github.com/path321/sound_spectrum_mcu.git

Usage

Connect the board via USB to your host PC. Make sure that no other STM32-based USB is connected to PC
Unzip plot_graph.zip Double click on plot_graph.exe
If you want to stop the live graph, check on the Button on the top right end of the GUI window

Versioning

This project uses Semantic Versioning. For a list of available versions, see the repository tag list.

How to Get Help

Please create a new issue on

https://github.com/path321/sound_spectrum_mcu/issues

License

This project is licensed under the MIT License - see LICENSE.md file for details.

Parts

Qty	Value	Footprint	References
8	100nF	Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder	C1, C3, C6, C7, C8, C12, C13, C14
4	1uF	Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder	C2, C4, C5, C9
4	MountingHole	MountingHole:MountingHole_3.2mm_M3_DIN965	H1, H2, H3, H4
2	10uF	Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder	C10, C11
2	1k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R2, R4
2	33pF	Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder	C15, C16
2	4.7k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R5, R6
2	ICS-43432	Samacsys:ICS43432	IC1-L1, IC2-R1
1	10k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R1
1	5.1k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R3
1	ABMM2-24.000MHZ-E2-T	Samacsys:ABMM2	Y1
1	AP2112K-3.3	Package_TO_SOT_SMD:SOT-23-5	U2
1	BOOT_SELECT	Jumper:SolderJumper-3_P1.3mm_Bridged2Bar12_Pad1.0x1.5mm	JP1
1	Conn_02x10_Counter_Clockwise	Connector_PinHeader_2.54mm:PinHeader_2x10_P2.54mm_Vertical	J2
1	LED - Green	LED_SMD:LED_0805_2012Metric_Pad1.15x1.40mm_HandSolder	D1
1	LED - Red	LED_SMD:LED_0805_2012Metric_Pad1.15x1.40mm_HandSolder	D2
1	STM32G473CBTx	Package_QFP:LQFP-48_7x7mm_P0.5mm	U1
1	SWD_CONN	Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical	J1
1	SW_DPST_x2	Button_Switch_THT:SW_PUSH_6mm	SW2
1	USBLC6-2SC6	Package_TO_SOT_SMD:SOT-23-6	U3
1	USB_C_Plug_USB2.0	Connector_USB:USB_C_Receptacle_GCT_USB4105-xx-A_16P_TopMnt_Horizontal	P1
1	~	Inductor_SMD:L_0805_2012Metric_Pad1.05x1.20mm_HandSolder	FB1

Questions

How big is the Sound spectrum v1 PCB?

It measures 85.6 × 54 mm and has 4 copper layers, 1.6 mm thick.

What parts does the Sound spectrum v1 use?

40 parts, built around the ICS-43432, AP2112K-3.3, USBLC6-2SC6 and ABMM2-24.000MHZ-E2-T. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Sound spectrum v1 KiCad files?

From the path321/sound_spectrum_mcu repository on GitHub, at the commit this page was made from: the board is pcb/sound_spectrum_v1.kicad_pcb and its schematic pcb/sound_spectrum_v1.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Sound spectrum v1 design in my own project?

Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).

Category and platform

Audio and music Sensors and measurement STM32

Topics

dsp mems stm32 pcb pyside6 fft frequency-domain microphone-audio-capture pyqt spectrum-analyzer

Project files

Show this board on your page

A live frame, for any web page

<iframe src="https://pcbkit.io/embed/boards/path321-sound-spectrum-mcu" title="Sound spectrum v1 in PCBKit" width="100%" height="480" style="border:0;border-radius:12px" allow="fullscreen" loading="lazy"></iframe>

A picture

<img src="https://pcbkit.io/embed/boards/path321-sound-spectrum-mcu.jpg" alt="Sound spectrum v1" width="1200" height="900">

A picture that opens the board, for a README

[![Sound spectrum v1](https://pcbkit.io/embed/boards/path321-sound-spectrum-mcu.jpg?size=s)](https://pcbkit.io/boards/path321-sound-spectrum-mcu)

Source

Repository: path321/sound_spectrum_mcu
Board file: pcb/sound_spectrum_v1.kicad_pcb
Commit: 713f2c6
Licence: MIT

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