4 layers31.5 × 47.5 mm
4 layers78 × 99 mm
- Size
- 78 × 99 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 63
- Nets
- 80
- Pads
- 311
- Tracks, vias
- 619, 128
- Pours
- 309
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 3 Apr 2026
- Updated
- 5 Apr 2026
Overview
Si4 is an open-source printed circuit board by aliadnani, from the aliadnani/si4 repository on GitHub. It is a 4-layer board of 78 × 99 mm with 63 parts on 80 nets, routed with 619 tracks and 128 vias.
It is built around the ESP32-S3-WROOM-1-N8 and STSPIN233. Its parts include 17 capacitors, 13 resistors, 7 switches, 6 ICs and 6 diodes. It belongs with the ESP32 boards of this library.
Main components
2
ESP32-S3-WROOM-1-N8
SMD,25.5x18mm-40℃~+85℃ -98.2dBm 2.4GHz 20.5dBm 355mA 3V~3.6V 95mA Bluetooth5.0 ESP32-S3 Chip On-board PCB Antenna UART、SPI、I2C、I2S、USB SMD,25.5x18mm WiFi Modules ROHSEspressif SystemsWiFi Modules
STSPIN233
QFN-16-EP(3x3)-40℃~+150℃ 1.8V~10V 3 400mΩ 80nA Three Phase QFN-16-EP(3x3) Brushless DC (BLDC) Motor Driver ROHSSTMicroelectronicsGate Drivers
Parts
63| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | 10 uF | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C3, C4, C6, C10, C11, C12 |
| 6 | LED | LED_SMD:LED_0805_2012Metric_Pad1.15x1.40mm_HandSolder | D1, D2, D3, D4, D5, D6 |
| 5 | 22 uF | Capacitor_SMD:C_1206_3216Metric_Pad1.33x1.80mm_HandSolder | C1, C2, C5, C7, C15 |
| 5 | SW_Push | PCM_Switch_Keyboard_Hotswap_Kailh:SW_Hotswap_Kailh_MX | SW2, SW3, SW4, SW5, SW7 |
| 4 | MountingHole_2.7mm_M2.5 | MountingHole:MountingHole_2.7mm_M2.5 | BL, BR, TL, TR |
| 3 | 1 uF | Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C8, C9, C13 |
| 3 | 10 K | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R5, R8, R11 |
| 2 | 10 nF | Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C16, C17 |
| 2 | 1k | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R12, R13 |
| 2 | 2R | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R1, R2 |
| 2 | 4.7 K | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R9, R10 |
| 2 | 5.1 K | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R4, R6 |
| 2 | TestPoint | TestPoint:TestPoint_Pad_1.0x1.0mm | TP1, TP2 |
| 1 | 1 uH | Inductor_SMD:L_Taiyo-Yuden_NR-40xx_HandSoldering | L1 |
| 1 | 100K | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R7 |
| 1 | 18650 | Connector_Wire:SolderWire-0.75sqmm_1x02_P7mm_D1.25mm_OD3.5mm | BT1 |
| 1 | 2.2 uF | Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C14 |
| 1 | 2.2 uH | Inductor_SMD:L_Taiyo-Yuden_NR-40xx_HandSoldering | L2 |
| 1 | 453K | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R3 |
| 1 | AS5600 (Encoder) | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U4 |
| 1 | Audio Hat I2S/I2C | Connector_PinSocket_1.27mm:PinSocket_1x10_P1.27mm_Vertical | J3 |
| 1 | Audio Hat Power | Connector_PinSocket_1.27mm:PinSocket_1x08_P1.27mm_Vertical | J4 |
| 1 | BLDC Gimbal Motor | Connector_Wire:SolderWire-0.75sqmm_1x03_P7mm_D1.25mm_OD3.5mm | J5 |
| 1 | ESP32-S3-WROOM-1 | RF_Module:ESP32-S3-WROOM-1 | U3 |
| 1 | IP5306_CK (BMS) | Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm | U1 |
| 1 | MCP23017_SS | Package_SO:SSOP-28_5.3x10.2mm_P0.65mm | U5 |
| 1 | SPI OLED Display | Connector_PinSocket_2.54mm:PinSocket_1x07_P2.54mm_Vertical | J1 |
| 1 | STSPIN233 | Package_DFN_QFN:VQFN-16-1EP_3x3mm_P0.5mm_EP1.8x1.8mm | U6 |
| 1 | SW_Push | Button_Switch_SMD:SW_SPST_TS-1088-xR020 | SW1 |
| 1 | SW_SPDT_MSM | Footprints:MTS-103 Switch | SW6 |
| 1 | TLV62569DBV (BMS Step Down) | Package_TO_SOT_SMD:SOT-23-5 | U2 |
| 1 | USB-C Connector | Connector_USB:USB_C_Receptacle_XKB_U262-16XN-4BVC11 | J2 |
Questions
How big is the Si4 PCB?
It measures 78 × 99 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Si4 use?
63 parts, built around the ESP32-S3-WROOM-1-N8 and STSPIN233. 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 Si4 KiCad files?
From the aliadnani/si4 repository on GitHub, at the commit this page was made from: the board is hardware/si4/si4.kicad_pcb and its schematic hardware/si4-hat/si4-hat.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Si4 design in my own project?
Its repository states no licence, so its author keeps all rights: ask aliadnani before reusing the design.
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