# ESP32 Ultrasonic Flow Meter ## Description USB-C powered ESP32 WiFi water flow meter for an external ultrasonic sensor on 3/4 inch PVC pipe, with protected 5V input, 3.3V regulation, programming header, reset/boot support, and status LEDs. ## Project Details - **Owner:** amirkat - **Created:** 5/20/2026 - **Last Updated:** 5/20/2026 - **Visibility:** Public ## Key Components ### D1 — [USBLC6-4SC6](https://www.flux.ai/kicad-part-library/usblc6-4sc6~cr3.md) - Manufacturer Part Number: USBLC6-4SC6 - Package or Case Code: SOT-23-6 - Role: Protection - Role Details: Low-capacitance ESD array for USB-C D+/D- and 5V input protection. - Part Type: Protection - Datasheet URL: https://www.st.com/resource/en/datasheet/usblc6-4.pdf - Manufacturer Name: Texas Instruments Inc. **Pins:** - GND [pin 2] - I/O1 [pin 1] - I/O2 [pin 3] - I/O3 [pin 4] - I/O4 [pin 6] - VBUS [pin 5] ### D2 — [LTST-C190KRKT](https://www.flux.ai/adrian95/ltst-c190krkt~3pw.md) - Part Type: LED - Role: Indicator - Datasheet URL: https://optoelectronics.liteon.com/upload/download/DS-22-99-0151/LTST-C190KRKT.pdf - Manufacturer Part Number: LTST-C190KRKT - Role Details: Red LED indicates 3.3V rail is present. - Manufacturer Name: Lite-On Inc. - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### D3 — [SML-D13FWT86C](https://www.flux.ai/jecstronic/sml-d13fwt86c~i2q.md) - Manufacturer Part Number: SML-D13FWT86C - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://fscdn.rohm.com/en/products/databook/datasheet/opto/led/chip_mono/sml-d13fwt86(c)-e.pdf - Manufacturer Name: Rohm Semiconductor - Role Details: Green LED driven by ESP32 firmware to indicate WiFi status. - Role: Indicator **Pins:** - A [pin 2] - K [pin 1] ### D4 — [APG1608QBC/D](https://www.flux.ai/jecstronic/apg1608qbcd~9qd.md) - Role Details: Blue LED driven by ESP32 firmware to indicate flow pulse activity. - Datasheet URL: https://www.kingbrightusa.com/images/catalog/SPEC/APG1608QBC-D.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Kingbright - Role: Indicator - Part Type: LED - Manufacturer Part Number: APG1608QBC/D **Pins:** - A [pin 2] - K [pin 1] ### F1 — [0805L110WR](https://www.flux.ai/adrian95/0805l110wr~h3i.md) - Role Details: 1.1A hold resettable fuse for protected USB input current path. - Manufacturer Name: Littelfuse Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Role: Protection - Datasheet URL: https://www.littelfuse.com/media?resourcetype=datasheets&itemid=3b1fa5dc-24aa-4363-b543-edb057c2fffa&filename=littelfuse_ptc_0805l_datasheet.pdf - Part Type: Fuse - Manufacturer Part Number: 0805L110WR **Pins:** - P1 [pin 1] - P2 [pin 2] ### J1 — [USB4105-GF-A](https://www.flux.ai/adrian95/usb4105-gf-a~im9.md) - Symbol Style: parametric-v1 - Part Type: USB C - Manufacturer Name: GCT - Datasheet URL: https://gct.co/files/specs/usb4105-spec.pdf - Manufacturer Part Number: USB4105-GF-A - Manufacturer Name: GCT - Role: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: USB-C sink connector for 5V VBUS and USB 2.0 D+/D- to ESP32-S3 native USB. **Pins:** - CC1 [pin A5] - CC2 [pin B5] - DN1 [pin A7] - DN2 [pin B7] - DP1 [pin A6] - DP2 [pin B6] - GND [pin A1_B12] - GND__1 [pin B1_A12] - SBU1 [pin A8] - SBU2 [pin B8] - SHELL_GND [pin SH1] - SHELL_GND__1 [pin SH2] - SHELL_GND__2 [pin SH3] - SHELL_GND__3 [pin SH4] - VBUS [pin A4_B9] - VBUS__1 [pin B4_A9] ### J2 — [0901301106](https://www.flux.ai/adrian95/0901301106~t1x.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 0901301106 - Datasheet URL: https://tools.molex.com/pdm_docs/sd/901301106_sd.pdf - Part Type: Connector - Role Details: 6-pin 2.54mm header for 3.3V, GND, pulse/interrupt, UART/I2C optional sensor interface signals. - Role: Connector - Manufacturer Name: Molex **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] ### J3 — [TSW-104-07-G-S](https://www.flux.ai/adrian95/tsw-104-07-g-s~983.md) - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: http://suddendocs.samtec.com/prints/tsw-xxx-xx-xxx-x-xx-xxx-mkt.pdf - Part Type: Connector - Manufacturer Part Number: TSW-104-07-G-S - Role: Connector - Manufacturer Name: Samtec Inc. - Package or Case Code: TSW10407GS - Role Details: 4-pin 2.54mm UART header: 3V3, GND, ESP32 TXD0, ESP32 RXD0. **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### S1 — [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 - Role Details: Momentary normally-open switch pulls ESP32 EN low for reset. - JLCPCB Part Class: Extended Part - LCSC Part Number: C720477 - 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 - Manufacturer Name: XUNPU(讯普) - Role: Switching - Manufacturer Part Number: TS-1088-AR02016 **Pins:** - 1 [pin 1] - 2 [pin 2] ### S2 — [TS-1088-AR02016](https://www.flux.ai/lcsc/ts-1088-ar02016~e3n1.md) - Package or Case Code: SW-SMD_L3.9-W3.0-P4.45 - 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 - JLCPCB Part Class: Extended Part - Role Details: Momentary normally-open switch pulls GPIO0 low to enter download mode. - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2409302330_XUNPU-TS-1088-AR02016_C720477.pdf - Part Type: Tactile Switches - Role: Switching **Pins:** - 1 [pin 1] - 2 [pin 2] ### U1 — [ESP32-S3-WROOM-1-N16R8](https://www.flux.ai/adrian95/esp32-s3-wroom-1-n16r8~fs1.md) - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.mouser.com/datasheet/2/891/esp32_s3_wroom_1_wroom_1u_datasheet_en-2930317.pdf - Manufacturer Part Number: ESP32-S3-WROOM-1-N16R8 - Role: Controller - Role Details: ESP32-S3 WiFi module for flow measurement, totalization, and wireless reporting. - Part Type: Module - Symbol Style: parametric-v1 - Manufacturer Name: Espressif Systems **Pins:** - 3V3 [pin 2] - EN [pin 3] - GND_1 [pin 1] - GND_10 [pin 48] - GND_11 [pin 49] - GND_2 [pin 40] - GND_3 [pin 41] - GND_4 [pin 42] - GND_5 [pin 43] - GND_6 [pin 44] - GND_7 [pin 45] - GND_8 [pin 46] - GND_9 [pin 47] - IO0 [pin 27] - IO1 [pin 39] - IO10 [pin 18] - IO11 [pin 19] - IO12 [pin 20] - IO13 [pin 21] - IO14 [pin 22] - IO15 [pin 8] - IO16 [pin 9] - IO17 [pin 10] - IO18 [pin 11] - IO19 [pin 13] - IO2 [pin 38] - IO20 [pin 14] - IO21 [pin 23] - IO3 [pin 15] - IO35 [pin 28] - IO36 [pin 29] - IO37 [pin 30] - IO38 [pin 31] - IO39 [pin 32] - IO4 [pin 4] - IO40 [pin 33] - IO41 [pin 34] - IO42 [pin 35] - IO45 [pin 26] - IO46 [pin 16] - IO47 [pin 24] - IO48 [pin 25] - IO5 [pin 5] - IO6 [pin 6] - IO7 [pin 7] - IO8 [pin 12] - IO9 [pin 17] - RXD0 [pin 36] - TXD0 [pin 37] ### U2 — [AP2112K-3.3TRG1](https://www.flux.ai/adrian95/ap2112k-33trg1~zlq.md) - Part Type: Integrated Circuit - Role Details: 3.3V LDO sized for ESP32 peak current; datasheet recommends at least 1uF input/output capacitors, using 10uF. - Role: Power Conversion - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: AP2112K-3.3TRG1 - Manufacturer Name: Diodes Incorporated - Datasheet URL: https://www.diodes.com/assets/Datasheets/AP2112.pdf - Symbol Style: parametric-v1 **Pins:** - EN [pin 3] - GND [pin 2] - NC [pin 4] - VIN [pin 1] - VOUT [pin 5] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/amirkat/esp32-ultrasonic-flow-meter~kl](https://www.flux.ai/amirkat/esp32-ultrasonic-flow-meter~kl).* --- *Generated from [https://www.flux.ai/amirkat/esp32-ultrasonic-flow-meter~kl](https://www.flux.ai/amirkat/esp32-ultrasonic-flow-meter~kl)*