# CarPresence v1.0 ## Description CarPresence - Production SBC (RK3568-class + ESP32) ## Project Details - **Owner:** firmaloizzo - **Created:** 2/28/2026 - **Last Updated:** 2/28/2026 - **Visibility:** Public ## Key Components ### J1 — [BM03B-SRSS-TB(LF)(SN)](https://www.flux.ai/lcsc/bm03b-srss-tblfsn~a391.md) - Role Details: JST-SH 3-pin SMD connector for WS2812B strip: Pin1 5V, Pin2 DIN, Pin3 GND. - Part Type: Wire To Board / Wire To Wire Connector - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_JST-BM03B-SRSS-TB-LF-SN_C160389.pdf - Role: Connector - Package: CONN-SMD-3P-P1.00_BM03B-SRSS-TB-LF-SN - Manufacturer Name: JST - Package or Case Code: CONN-SMD-3P-P1.00_BM03B-SRSS-TB-LF-SN - Product Info Url: https://lcsc.com/product-detail/Others_JST-Sales-America__JST-Sales-America-BM03B-SRSS-TB-LF-SN_C160389.html - Manufacturer Part Number: BM03B-SRSS-TB(LF)(SN) - LCSC Part Number: C160389 - JLCPCB Part Class: Extended Part **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] ### U1 — [BM03B-SRSS-TB(LF)(SN)](https://www.flux.ai/lcsc/bm03b-srss-tblfsn~a391.md) - Role Details: JST-SH 3-pin SMD connector for WS2812B strip: Pin1 5V, Pin2 DIN, Pin3 GND; placed on I/O edge. - Role: Connector - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_JST-BM03B-SRSS-TB-LF-SN_C160389.pdf - Part Type: Wire To Board / Wire To Wire Connector - Product Info Url: https://lcsc.com/product-detail/Others_JST-Sales-America__JST-Sales-America-BM03B-SRSS-TB-LF-SN_C160389.html - Package or Case Code: CONN-SMD-3P-P1.00_BM03B-SRSS-TB-LF-SN - Manufacturer Name: JST - JLCPCB Part Class: Extended Part - Package: CONN-SMD-3P-P1.00_BM03B-SRSS-TB-LF-SN - LCSC Part Number: C160389 - Manufacturer Part Number: BM03B-SRSS-TB(LF)(SN) **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] ### U1 — [74HCT125PW-Q100J](https://www.flux.ai/lcsc/74hct125pw-q100j~9anh.md) - Manufacturer Name: Nexperia(安世) - Package or Case Code: TSSOP-14_L5.0-W4.4-P0.65-LS6.4-BL - JLCPCB Part Class: Extended Part - LCSC Part Number: C545658 - Role: Level Shifter - Product Info Url: https://lcsc.com/product-detail/presales_Nexperia-74HCT125PW-Q100J_C545658.html - Manufacturer Part Number: 74HCT125PW-Q100J - Package: TSSOP-14 - Role Details: 74HCT125 (AEC-Q100) powered at 5V; one channel used to buffer ESP32 3.3V GPIO to WS2812B DIN; OE tied active. - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_2410010201_Nexperia-74HCT125PW-Q100J_C545658.pdf - Part Type: Buffers / Drivers **Pins:** - ~{1OE} [pin 1] - ~{2OE} [pin 4] - ~{3OE} [pin 10] - ~{4OE} [pin 13] - 1A [pin 2] - 1Y [pin 3] - 2A [pin 5] - 2Y [pin 6] - 3A [pin 9] - 3Y [pin 8] - 4A [pin 12] - 4Y [pin 11] - GND [pin 7] - VCC [pin 14] ### U1 — [74HCT125PW-Q100J](https://www.flux.ai/lcsc/74hct125pw-q100j~9anh.md) - Package or Case Code: TSSOP-14_L5.0-W4.4-P0.65-LS6.4-BL - JLCPCB Part Class: Extended Part - Manufacturer Name: Nexperia - Role: Level Shifter - LCSC Part Number: C545658 - Manufacturer Part Number: 74HCT125PW-Q100J - Product Info Url: https://lcsc.com/product-detail/presales_Nexperia-74HCT125PW-Q100J_C545658.html - Part Type: Buffers / Drivers - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_2410010201_Nexperia-74HCT125PW-Q100J_C545658.pdf - Package: TSSOP-14 - Role Details: 74HCT125 (AEC-Q100) powered at 5V; one channel buffers ESP32 3.3V GPIO to WS2812B DIN; OE tied active. **Pins:** - ~{1OE} [pin 1] - ~{2OE} [pin 4] - ~{3OE} [pin 10] - ~{4OE} [pin 13] - 1A [pin 2] - 1Y [pin 3] - 2A [pin 5] - 2Y [pin 6] - 3A [pin 9] - 3Y [pin 8] - 4A [pin 12] - 4Y [pin 11] - GND [pin 7] - VCC [pin 14] ### U1 — [74HCT125PW,118](https://www.flux.ai/lcsc/74hct125pwc118~bnp4.md) - JLCPCB Part Class: Extended Part - Role: Level Shifter - LCSC Part Number: C131316 - Package: TSSOP-14 - Manufacturer Name: Nexperia(安世) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2407241026_Nexperia-74HCT125PW-118_C131316.pdf - Part Type: Buffers / Drivers - Role Details: 74HCT125 powered at 5V; single channel used to buffer ESP32 3.3V GPIO to WS2812B 5V DIN; OE tied active. - Manufacturer Part Number: 74HCT125PW,118 - Package or Case Code: TSSOP-14_L5.0-W4.4-P0.65-LS6.4-BL - Product Info Url: https://lcsc.com/product-detail/74-Series_Nexperia_74HCT125PW-118_74HCT125PW-118_C131316.html **Pins:** - ~{1OE} [pin 1] - ~{2OE} [pin 4] - ~{3OE} [pin 10] - ~{4OE} [pin 13] - 1A [pin 2] - 1Y [pin 3] - 2A [pin 5] - 2Y [pin 6] - 3A [pin 9] - 3Y [pin 8] - 4A [pin 12] - 4Y [pin 11] - GND [pin 7] - VCC [pin 14] ### U2 — [BM03B-SRSS-TB(LF)(SN)](https://www.flux.ai/lcsc/bm03b-srss-tblfsn~a391.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_JST-BM03B-SRSS-TB-LF-SN_C160389.pdf - Part Type: Wire To Board / Wire To Wire Connector - Role Details: JST-SH 3-pin SMD connector for WS2812B strip: Pin1 5V, Pin2 DIN, Pin3 GND. - Product Info Url: https://lcsc.com/product-detail/Others_JST-Sales-America__JST-Sales-America-BM03B-SRSS-TB-LF-SN_C160389.html - Package or Case Code: CONN-SMD-3P-P1.00_BM03B-SRSS-TB-LF-SN - Package: CONN-SMD-3P-P1.00_BM03B-SRSS-TB-LF-SN - Manufacturer Name: JST - Role: Connector - JLCPCB Part Class: Extended Part - LCSC Part Number: C160389 - Manufacturer Part Number: BM03B-SRSS-TB(LF)(SN) **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] ### U3 — [74HCT125PW-Q100J](https://www.flux.ai/lcsc/74hct125pw-q100j~9anh.md) - Part Type: Buffers / Drivers - Datasheet URL: https://www.lcsc.com/datasheet/lcsc_datasheet_2410010201_Nexperia-74HCT125PW-Q100J_C545658.pdf - Package: TSSOP-14 - Manufacturer Part Number: 74HCT125PW-Q100J - Product Info Url: https://lcsc.com/product-detail/presales_Nexperia-74HCT125PW-Q100J_C545658.html - Role Details: 74HCT125 (AEC-Q100) powered at 5V; one channel used to buffer ESP32 3.3V GPIO to WS2812B DIN; OE tied active. - Role: Level Shifter - LCSC Part Number: C545658 - Package or Case Code: TSSOP-14_L5.0-W4.4-P0.65-LS6.4-BL - JLCPCB Part Class: Extended Part - Manufacturer Name: Nexperia **Pins:** - ~{1OE} [pin 1] - ~{2OE} [pin 4] - ~{3OE} [pin 10] - ~{4OE} [pin 13] - 1A [pin 2] - 1Y [pin 3] - 2A [pin 5] - 2Y [pin 6] - 3A [pin 9] - 3Y [pin 8] - 4A [pin 12] - 4Y [pin 11] - GND [pin 7] - VCC [pin 14] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/firmaloizzo/carpresence-v1p0~o7](https://www.flux.ai/firmaloizzo/carpresence-v1p0~o7).* --- *Generated from [https://www.flux.ai/firmaloizzo/carpresence-v1p0~o7](https://www.flux.ai/firmaloizzo/carpresence-v1p0~o7)*