6 layers100 × 100 mm
Ai vision
embeddedci-com/pcb-trace-length-analyzer
Two of them, and the difference between them is the point.
370 parts3Apache-2.0
4 layers52.9 × 70.7 mm
Solution design
featherfly12/speaker-pcbIn this github, there is a pcb design that has a total of 1 song! Download the KiCAD/PCB files in JLCPCB for the design schematic and files! Download the .zip files in firmware/media for the code! Once you've soldered…
- Size
- 52.9 × 70.7 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 56
- Nets
- 64
- Pads
- 203
- Tracks, vias
- 417, 84
- Pours
- 10
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 3 Jul 2026
- Updated
- 7 Aug 2026
Overview
Solution design is an open-source printed circuit board by featherfly12, from the featherfly12/speaker-pcb repository on GitHub. It is a 4-layer board of 52.9 × 70.7 mm with 56 parts on 64 nets, routed with 417 tracks and 84 vias.
It is built around the STM32L433CCT6, MAX98357AETE+T and W25Q128JVEIQ, with the AP2112K-3.3TRG1, 3362P-1-502LF and ECS-80-12-33-JGN-TR among its other parts. Its parts include 22 capacitors, 16 resistors, 5 ICs, 3 diodes and 2 connectors. It belongs with the STM32 boards of this library.
Main components
10
STM32L433CCT6
LQFP-48(7x7)-40℃~+85℃ 1.71V~3.6V 12bit 12bit 256KB 32 Bit 38 64KB 80MHz ARM Cortex-M4 Built-in FLASH LQFP-48(7x7) Microcontrollers (MCU/MPU/SOC) ROHSSTMicroelectronicsMicrocontrollers (MCU/MPU/SOC)
MAX98357AETE+T
TQFN-16-EP(3x3)-40℃~+85℃ 2.4mA 2.5V~5.5V 3.2Wx1@4Ω 77dB 92% Automatic mute/no-noise switch、Enable/shutdown function、Filterless architecture Class D TQFN-16-EP(3x3) Audio Amplifiers ROHSMaxim Integrated (Analog Devices)Audio Amplifiers
W25Q128JVEIQ
WSON-8-EP(6x8)-40℃~+85℃ 100,000 cycles 10uA 128Mbit 133MHz 2.7V~3.6V 20 Years Power-on reset、Hardware write protection、Software write protection、Write enable latch、Absolute write protection、Power lock protection SPI WSON-8-EP(6x8) NOR FLASH ROHSWinbondNAND FLASH
AP2112K-3.3TRG1
SOT-25-5-40℃~+85℃@(Ta) 1 250mV@(600mA) 3.3V 50uVrms 55uA 600mA 65dB@(1kHz) 6V Fixed Over Current Protection、Thermal Shutdown、Enable control Positive SOT-25-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSDiodes IncorporatedVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
3362P-1-502LF
插件-3P,7x6.8mm1 500mW 5kΩ ±10% ±150ppm/℃ 插件-3P,7x6.8mm Potentiometers, Variable Resistors ROHSjieerruiPotentiometers & Variable Resistors
ECS-80-12-33-JGN-TR
SMD3225-4P-40℃~+85℃ 12pF 400Ω 8MHz ±20ppm ±30ppm SMD3225-4P Crystals ROHSECSCrystals
PESD3V3L1BA
--65℃~+150℃ 1 101pF 18A@8/20us 26V 3.3V 500W 6.9V 90nA Bidirectional ESD SOD-323 ESD and Surge Protection (TVS/ESD) ROHSNexperiaESD And Surge Protection (TVS/ESD)
PESD3V3L4UG,115-JSM
SOT-353-40℃~+125℃ 150W@8/20us 1mA 5V 7.2V 90pF ESD Four channels IEC 61000-4-2 Unidirectional SOT-353 ESD and Surge Protection (TVS/ESD) ROHSJSMSEMIUncategorised
PJ-002AH
插件-25℃~+85℃ 24V 2mm 5A 6.5mm DC Power Jack Right Angle 插件 DC Power Connectors ROHSCUIDC Power Connectors
SMAJ13A
DO-214AC(SMA)-55℃~+150℃ 13V 15.9V 18.6A 1uA 21.5V 400W@10/1000us IEC 61000-4-2 TVS Unidirectional DO-214AC(SMA) ESD and Surge Protection (TVS/ESD) ROHShongjiachengESD And Surge Protection (TVS/ESD)
README
README.mdSpeaker PCB
In this github, there is a pcb design that has a total of 1 song! Download the KiCAD/PCB files in JLCPCB for the design schematic and files! Download the .zip files in firmware/media for the code! Once you've soldered your PCB (parts below) OR you bought it from a PCB maker (like i did), you can flash the music onto the chip using an external loader and STM32CubeProgrammer. The external loader for this custom PCB was written in the folder firmware/W25Q128_HAL, and the actual compiled loader file is W25Q128_STM32L433_HAL.stldr. Once the external memory is programmed with the song, the STM32 itself can be flashed with the music_player project using STM32CubeIDE. These programs were written with the help of Claude Code / Sonnet 4.6. (and john heath)
some other info below...
| Part | What it is | What it does in this circuit |
|---|---|---|
| STM32L433CCT6 | Microcontroller | Runs your code — reads the song from flash memory and streams it to the speaker amplifier over I2S |
| W25Q128JVEIQ | 16 MB flash memory chip | Stores the raw audio file (like a tiny solid-state drive) so the microcontroller can play it back |
| MAX98357AETE+T | I2S audio amplifier | Takes the digital audio stream from the microcontroller and amplifies it directly via pulse-width modulation (PWM) — rapid switching whose pulse widths track the signal, which the speaker smooths back into sound. This switching design is what makes it a class-D amplifier, and what lets it drive a speaker efficiently from such a small chip. |
| AP2112K-3.3TRG1 | 3.3V Low-dropout Regulator (LDO) | Steps down the input voltage to the stable 3.3V that the microcontroller and other chips need to operate safely. This can eliminate most noise from the power supply, making the 3.3V "clean" power. |
| SMAJ13A | TVS (transient voltage suppression) diode | Prevents voltage spikes on the power input. |
| PESD3V3L4UG,115 | 4-channel ESD protection array | Guards four signal lines at once against static electricity (ESD). Static can silently kill chips when you touch their pins! |
| PESD3V3L1BA | Single-channel ESD protection diode | Same idea as above, but for one signal line. |
| ECS-80-12-33-JGN-TR | 8MHz Crystal | A crystal that oscillates within 20 ppm of 8MHz when driven by the MCU (with some helper capacitors). This makes the clock of the MCU much more precise, and prevents the frequency of the song from drifting while it is playing. |
Programming the Board
Music from an MP3 file is converted into pure binary 16-bit data at 31.25kHz using scripts in firmware/media. The output, media.bin, may be flashed onto the chip using an external loader and STM32CubeProgrammer. The external loader for this custom PCB was written in the folder firmware/W25Q128_HAL, and the actual compiled loader file is W25Q128_STM32L433_HAL.stldr. Once the external memory is programmed with the song, the STM32 itself can be flashed with the music_player project using STM32CubeIDE.
These programs were written with the help of Claude Code / Sonnet 4.6.
Parts
56| Qty | Value | Footprint | References |
|---|---|---|---|
| 10 | 0.1uF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C4, C5, C9, C10, C11, C13, C15, C21, C22, C23 |
| 9 | 33 | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R3, R4, R5, R6, R7, R8, R9, R10, R11 |
| 6 | 10k | Resistor_SMD:R_1206_3216Metric_Pad1.30x1.75mm_HandSolder | R1, R2, R12, R13, R14, R15 |
| 3 | 1uF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C8, C19, C20 |
| 3 | TestPoint | TestPoint:TestPoint_Loop_D2.54mm_Drill1.5mm_Beaded | TP1, TP2, TP3 |
| 2 | 10uF | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C14, C18 |
| 2 | 18pF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C2, C3 |
| 2 | 22uF | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C1, C16 |
| 1 | 10nF | Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C7 |
| 1 | 220uF | Capacitor_THT:CP_Radial_D10.0mm_P5.00mm | C12 |
| 1 | 3362P-1-502LF | project_footprints:POT_3362P | R16 |
| 1 | 4.7uF | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C6 |
| 1 | 4.7uH | project_footprints:IND_NRS6028T0R9NMGJV_TAY | L1 |
| 1 | AP2112K-3.3TRG1 | project_footprints:SOT_RG1_DIO-M | U5 |
| 1 | AP63205WU-7 | project_footprints:SOIC_05WU-7_DIO-M | U4 |
| 1 | Conn_ARM_SWD_TagConnect_TC2030 | Connector:Tag-Connect_TC2030-IDC-FP_2x03_P1.27mm_Vertical | J1 |
| 1 | ECS-80-12-33-JGN-TR | project_footprints:XTAL_ECS-240-8-33-AGN-TR | Y1 |
| 1 | MAX98357AETE+T | project_footprints:21-0136I_T1633-4_MXM-M | U3 |
| 1 | PESD3V3L1BA | Diode_SMD:D_SOD-323_HandSoldering | D3 |
| 1 | PESD3V3L4UG,115 | project_footprints:PESD3V3L4UG115 | D2 |
| 1 | PJ-002AH | project_footprints:CUI_PJ-002AH | J2 |
| 1 | SMAJ13A | project_footprints:DIONM5126X250N | D1 |
| 1 | STM32L433CCT6 | project_footprints:QFP50P900X900X160-48N | U1 |
| 1 | Speaker | project_footprints:CES-46257-24-L200 | LS1 |
| 1 | Switch | project_footprints:PTS647SK70SMTR2LFS | S1 |
| 1 | TestPoint | TestPoint:TestPoint_Loop_D1.80mm_Drill1.0mm_Beaded | TP4 |
| 1 | W25Q128JVEIQ | project_footprints:WSON_128JVEIQ_WIN-M | U2 |
Questions
How big is the Solution design PCB?
It measures 52.9 × 70.7 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Solution design use?
56 parts, built around the STM32L433CCT6, MAX98357AETE+T, W25Q128JVEIQ and AP2112K-3.3TRG1. 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 Solution design KiCad files?
From the featherfly12/speaker-pcb repository on GitHub, at the commit this page was made from: the board is music player!/solution-design.kicad_pcb and its schematic music player!/solution-design.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Solution design design in my own project?
Its repository states no licence, so its author keeps all rights: ask featherfly12 before reusing the design.
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