# ESP32-C3 Smartwatch PCB ## Description Production-grade ESP32-C3 smartwatch PCB with visible, wrist-contact, and outward-facing sensor orientation zones for JLCPCB 2-layer manufacturing. ## Project Details - **Owner:** eepbeep - **Created:** 5/5/2026 - **Last Updated:** 5/5/2026 - **Visibility:** Public ## Key Components ### D1 — [1N5819HW-7-F](https://www.flux.ai/jecstronic/1n5819hw-7-f~x5v.md) - Manufacturer Part Number: 1N5819HW-7-F - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.diodes.com/assets/Datasheets/ds30217.pdf - Manufacturer Name: Diodes Incorporated - Part Type: Diode **Pins:** - A [pin 2] - K [pin 1] ### DS1 — [AOM12864A0-1.3BW-ANO](https://www.flux.ai/cherepanyadima/aom12864a0-1p3bw-ano~8l.md) - Role: Top-facing integrated OLED display - Part Type: Optoelectronic Devices - Role Details: Must be placed on top side, centered under the display window, screen facing up; replaces FPC-only OLED implementation. - Datasheet URL: https://www.snapeda.com/parts/AOM12864A0-1.3BW-ANO/Orient%20Display/datasheet/ - Manufacturer Name: Orient Display - Manufacturer Part Number: AOM12864A0-1.3BW-ANO - Symbol Style: Parametric - Package or Case Code: Module **Pins:** - C\S\\ [pin 7] - DC [pin 6] - GND [pin 1] - R\S\T\\ [pin 5] - SCL [pin 3] - SDA [pin 4] - VDD [pin 2] ### J1 — [USB-C 2.0 Receptacle](https://www.flux.ai/vritzka/usb-c-2p0-receptacle~h8.md) - Purchase Url: https://www.digikey.com/en/products/detail/gct/USB4105-GF-A/11198441 - Part Type: USB C - Manufacturer Part Number: USB4105-GF-A - Manufacturer Name: GTC - Datasheet URL: https://gct.co/files/drawings/usb4105.pdf **Pins:** - CC1 [pin 6] - CC2 [pin 12] - D- [pin 9] - D- [pin 7] - D+ [pin 10] - D+ [pin 8] - GND [pin 15] - GND [pin 1] - GND [pin 16] - GND [pin 2] - SBU1 [pin 11] - SBU2 [pin 5] - Shield [pin 16] - VBUS [pin 14] - VBUS [pin 13] - VBUS [pin 4] - VBUS [pin 3] ### J2 — [S2B-PH-SM4-TB(LF)(SN)](https://www.flux.ai/adrian95/s2b-ph-sm4-tblfsn~b96.md) - Connector Type: JST-PH - Connector Positions: 2 - Manufacturer Name: JST Sales America Inc. - Role: Rechargeable LiPo battery connector - Manufacturer Part Number: S2B-PH-SM4-TB(LF)(SN) - Part Type: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Connector Pitch: 2mm - Role Details: 2-pin JST-PH LiPo connector: P1=VBAT positive, P2=GND negative; add BAT+/BAT- polarity marking in silkscreen. - Datasheet URL: https://www.jst-mfg.com/product/pdf/eng/ePH.pdf **Pins:** - P1 [pin 1] - P2 [pin 2] ### SW1 — [SS12D07VG2](https://www.flux.ai/lcsc/ss12d07vg2~bb90.md) - LCSC Part Number: C2681571 - Part Type: Slide Switches - Role: Load-share power switch - JLCPCB Part Class: Extended Part - Role Details: SS12D07VG2 user-required slide switch in VBAT-to-SYS_IN path; VBUS feeds SYS_IN through Schottky D1 for USB load sharing. - Manufacturer Part Number: SS12D07VG2 - Manufacturer Name: SHOU HAN(首韩) - Package or Case Code: SW-TH_SS12D07VG4 **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] ### SW2 — [TS-1088-AR02016](https://www.flux.ai/lcsc/ts-1088-ar02016~e3n1.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2409302330_XUNPU-TS-1088-AR02016_C720477.pdf - Part Type: Tactile Switches - JLCPCB Part Class: Extended Part - Manufacturer Name: XUNPU(讯普) - Manufacturer Part Number: TS-1088-AR02016 - Product Info Url: https://lcsc.com/product-detail/Tactile-Switches_XUNPU-TS-1088-AR02016_C720477.html - LCSC Part Number: C720477 - Package or Case Code: SW-SMD_L3.9-W3.0-P4.45 **Pins:** - 1 [pin 1] - 2 [pin 2] ### SW3 — [TS-1088-AR02016](https://www.flux.ai/lcsc/ts-1088-ar02016~e3n1.md) - Part Type: Tactile Switches - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2409302330_XUNPU-TS-1088-AR02016_C720477.pdf - Manufacturer Name: XUNPU(讯普) - JLCPCB Part Class: Extended Part - Manufacturer Part Number: TS-1088-AR02016 - Product Info Url: https://lcsc.com/product-detail/Tactile-Switches_XUNPU-TS-1088-AR02016_C720477.html - Package or Case Code: SW-SMD_L3.9-W3.0-P4.45 - LCSC Part Number: C720477 **Pins:** - 1 [pin 1] - 2 [pin 2] ### TP1 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Harwin Inc. - Part Type: Test point - Manufacturer Part Number: S1751-46R **Pins:** - P1 ### TP10 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Role Details: ESP32-C3 RXD UART test pad - Part Type: Test point - Manufacturer Part Number: S1751-46R - Role: Debug test pad - Manufacturer Name: Harwin Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf **Pins:** - P1 ### TP2 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Part Type: Test point - Manufacturer Part Number: S1751-46R - Manufacturer Name: Harwin Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf **Pins:** - P1 ### TP3 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - Manufacturer Name: Harwin Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Test point - Manufacturer Part Number: S1751-46R **Pins:** - P1 ### TP4 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Manufacturer Part Number: S1751-46R - Part Type: Test point - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Harwin Inc. **Pins:** - P1 ### TP5 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Manufacturer Name: Harwin Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - Part Type: Test point - Manufacturer Part Number: S1751-46R **Pins:** - P1 ### TP6 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Harwin Inc. - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - Manufacturer Part Number: S1751-46R - Part Type: Test point **Pins:** - P1 ### TP7 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Harwin Inc. - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - Part Type: Test point - Manufacturer Part Number: S1751-46R **Pins:** - P1 ### TP8 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Harwin Inc. - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf - Part Type: Test point - Manufacturer Part Number: S1751-46R **Pins:** - P1 ### TP9 — [S1751-46R](https://www.flux.ai/adrian95/s1751-46r~7b.md) - Part Type: Test point - Manufacturer Part Number: S1751-46R - Role: Debug test pad - Manufacturer Name: Harwin Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: ESP32-C3 TXD UART test pad - Datasheet URL: https://content.harwin.com/m/c5b84e6a45e9b9f6/original/DRG-02202-Technical-Drawing-Datasheet-S1751R-pdf.pdf **Pins:** - P1 ### U1 — [ESP32-C3-WROOM-02-N4](https://www.flux.ai/lcsc/esp32-c3-wroom-02-n4~877i.md) - Part Type: RF Transceiver ICs - Voltage Supply: 3V ~ 3.6V - Manufacturer Name: ESPRESSIF(乐鑫) - Operating Temperature: -40°C ~ 85°C (TA) - Frequency: 2.4GHz - JLCPCB Part Class: Extended Part - LCSC Part Number: C2934560 - Package or Case Code: BULETM-SMD_ESPRESSIF_ESP32-C3-WROOM-02-N4-4MB - Manufacturer Part Number: ESP32-C3-WROOM-02-N4 **Pins:** - 3V3 [pin 1] - EN [pin 2] - EP [pin 19] - GND [pin 9] - IO0 [pin 18] - IO1 [pin 17] - IO10 [pin 10] - IO18 [pin 13] - IO19 [pin 14] - IO2 [pin 16] - IO3 [pin 15] - IO4 [pin 3] - IO5 [pin 4] - IO6 [pin 5] - IO7 [pin 6] - IO8 [pin 7] - IO9 [pin 8] - RXD [pin 11] - TXD [pin 12] ### U2 — [MCP73831T-2ATI/OT](https://www.flux.ai/adrian95/mcp73831t-2atiot~46p.md) - Part Type: Integrated Circuit - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: MCP73831 retained instead of TP4056 for compact SOT-23-5 assembly; simple linear charger without integrated power path, paired with Schottky/load-share switch topology. - Role: LiPo charger - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/MCP73831-Family-Data-Sheet-DS20001984H.pdf - Manufacturer Part Number: MCP73831T-2ATI/OT - Manufacturer Name: Microchip Technology **Pins:** - PROG [pin 5] - STAT [pin 1] - VBAT [pin 3] - VDD [pin 4] - VSS [pin 2] ### U3 — [AP2112K-3.3TRG1](https://www.flux.ai/adrian95/ap2112k-33trg1~zlq.md) - Manufacturer Name: Diodes Incorporated - Part Type: Integrated Circuit - Symbol Style: parametric-v1 - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.diodes.com/assets/Datasheets/AP2112.pdf - Manufacturer Part Number: AP2112K-3.3TRG1 **Pins:** - EN [pin 3] - GND [pin 2] - NC [pin 4] - VIN [pin 1] - VOUT [pin 5] ### U4 — [MAX30102EFD+T](https://www.flux.ai/vasy_skral/max30102efdplust~r7h.md) - Manufacturer Name: Maxim Integrated - Datasheet URL: https://datasheets.maximintegrated.com/en/ds/MAX30102.pdf - Part Type: Integrated Circuit - Symbol Style: Parametric - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: MAX30102EFD+T - Role Details: MAX30102 optical heart-rate/SpO2 sensor. Non-negotiable bottom/wrist-side skin-contact placement; align optical window to enclosure cutout; keep optical aperture copper/pour/solder-mask free; flush or slightly recessed relative to enclosure contact plane. **Pins:** - ~INT [pin 13] - GND [pin 12] - IR_DRV [pin 6] - NC [pin 8] - NC [pin 14] - NC [pin 1] - NC [pin 7] - PGND [pin 4] - R_DRV [pin 5] - SCL [pin 2] - SDA [pin 3] - VDD [pin 11] - VLED+ [pin 10] - VLED+ [pin 9] ### U5 — [MLX90614ESF-ACC-000-SP](https://www.flux.ai/jecstronic/mlx90614esf-acc-000-sp~si.md) - Datasheet URL: https://media.melexis.com/-/media/files/documents/datasheets/MLX90614-datasheet-melexis.pdf - Manufacturer Part Number: MLX90614ESF-ACC-000-SP - Part Type: Sensor - Role Details: MLX90614 IR temperature sensor. Place on bottom/wrist side only if measuring skin temperature; align sensing can/aperture with skin-contact IR window; maintain same contact plane as MAX30102; keep thermal isolation from AP2112K/MCP73831 and no copper in aperture path. - Manufacturer Name: Melexis Technologies NV - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - PWM_SDA [pin 2] - SCL_Vz [pin 1] - VDD [pin 3] - VSS [pin 4] ### U6 — [MPU-6050](https://www.flux.ai/vasyl/mpu-6050~qg.md) - Manufacturer Part Number: MPU-6050 - Role Details: Bare MPU-6050 retained instead of GY-521 module for compact JLC assembly and lower smartwatch stack height; I2C address AD0 tied low. - Datasheet URL: https://invensense.tdk.com/wp-content/uploads/2015/02/MPU-6000-Datasheet1.pdf - Part Type: Integrated Circuit - Role: IMU sensor - Manufacturer Name: TDK InvenSense **Pins:** - 25 [pin 25] - AD0 [pin 9] - AUX_CL [pin 7] - AUX_DA [pin 6] - CLKIN [pin 1] - CPOUT [pin 20] - FSYNC [pin 11] - GND [pin 18] - INT [pin 12] - NC [pin 4] - NC [pin 15] - NC [pin 2] - NC [pin 16] - NC [pin 17] - NC [pin 5] - NC [pin 3] - NC [pin 14] - REGOUT [pin 10] - RESV [pin 19] - RESV [pin 22] - RESV [pin 21] - SCL [pin 23] - SDA [pin 24] - VDD [pin 13] - VLOGIC [pin 8] ### U7 — [USBLC6-4SC6](https://www.flux.ai/lcsc/usblc6-4sc6~kfr1.md) - Part Type: ESD Protection Devices - Manufacturer Name: ST(意法半导体) - LCSC Part Number: C111212 - Product Info Url: https://lcsc.com/product-detail/Diodes-ESD_STMicroelectronics_USBLC6-4SC6_USBLC6-4SC6_C111212.html - Role: ESD Protection - Manufacturer Part Number: USBLC6-4SC6 - Role Details: USB-C VBUS and D+/D- low-capacitance TVS near connector - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1810130920_STMicroelectronics-USBLC6-4SC6_C111212.pdf - JLCPCB Part Class: Extended Part - Package or Case Code: SOT-23-6_L2.9-W1.6-P0.95-LS2.8-BL **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/eepbeep/esp32-c3-smartwatch-pcb~x3](https://www.flux.ai/eepbeep/esp32-c3-smartwatch-pcb~x3).* --- *Generated from [https://www.flux.ai/eepbeep/esp32-c3-smartwatch-pcb~x3](https://www.flux.ai/eepbeep/esp32-c3-smartwatch-pcb~x3)*