# neckdown\-culling\-retest

## Description

USB\-C\-powered ESP32 controller for a 12 V RS485 ultrasonic flow sensor on a 3/4\-inch PVC pipe, with WiFi telemetry, flow totalization, status indicators, and UART programming\.

## Project Details

- **Owner:** me\-devin
- **Created:** 8/25/2026
- **Last Updated:** 8/25/2026
- **Visibility:** Public
- **Stars:** 1
- **Copies:** 33

## Key Components

### D1 — [SMF5\.0A](https://flux.ai/lcsc/smf5p0a~bz6b.md)

- Package or Case Code: SOD\-123FL\_L2\.8\-W1\.8\-LS3\.6\-RD
- JLCPCB Part Class: Extended Part
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2990427\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=T1kIXgFeT1NaU1RXQFBbUlUHT1cKU1NXFVBeX1VSTlAxVlNRTlBbUVFXRldaXzsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- LCSC Part Number: C2990427
- Diode Type: Schottky Diode
- Part Type: TVS
- Max Reverse Voltage: 5V
- Manufacturer Name: Liown\(里阳半导体\)
- Functional Group: USB Input
- Manufacturer Part Number: SMF5\.0A
- Forward Voltage: 0\.45V to 0\.55V \(at 1A\)V

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### D2 — [SS14](https://flux.ai/jecstronic/ss14~ri4.md)

- Manufacturer Name: Slkor\(SLKORMICRO Elec\.\)
- Functional Group: Power 12V Boost
- Datasheet URL: https://datasheet\.lcsc\.com/lcsc/1912111437\_Slkor\-SLKORMICRO\-Elec\-\-SS14\_C444721\.pdf
- Part Type: Diode
- Manufacturer Part Number: SS14
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- Anode [pin A]
- Cathode [pin C]

### D3 — [SM712](https://flux.ai/lcsc/sm712~9760.md)

- Forward Voltage: 0\.45V to 0\.55V
- Part Type: TVS
- LCSC Part Number: C502564
- Package or Case Code: SOT\-23\-3\_L2\.9\-W1\.6\-P1\.90\-LS2\.8\-BR
- Max Reverse Voltage: 20V
- JLCPCB Part Class: Extended Part
- Diode Type: Schottky Diode
- Functional Group: RS485
- Product Info Url: https://lcsc\.com/product\-detail/TVS\_MDD\-Microdiode\-Electronics\-SM712\_C502564\.html
- Manufacturer Name: MDD
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2407101112\_MDD\-Microdiode\-Semiconductor\-SM712\_C502564\.pdf
- Manufacturer Part Number: SM712

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]

### F1 — [0805L110WR](https://flux.ai/adrian95/0805l110wr~h3i.md)

- Functional Group: USB Input
- Manufacturer Name: Littelfuse Inc\.
- Manufacturer Part Number: 0805L110WR
- Datasheet URL: https://www\.littelfuse\.com/media?resourcetype=datasheets&itemid=3b1fa5dc\-24aa\-4363\-b543\-edb057c2fffa&filename=littelfuse\_ptc\_0805l\_datasheet\.pdf
- Part Type: Fuse
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- P1 [pin 1]
- P2 [pin 2]

### J1 — [USB4215\-03\-A](https://flux.ai/adrian95/usb4215-03-a~kg3.md)

- Datasheet URL: https://gct\.co/files/specs/usb4215\-spec\.pdf
- Part Type: USB C
- Symbol Style: parametric\-v1
- Package or Case Code: GCT\_USB4215\-03\-A\_REVA
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: GCT
- Functional Group: USB Input
- Manufacturer Part Number: USB4215\-03\-A

**Pins:**
- CC1 [pin A5]
- CC2 [pin B5]
- DN1 [pin A7]
- DN2 [pin B7]
- DP1 [pin A6]
- DP2 [pin B6]
- GND\_A [pin A1\_B12]
- GND\_B [pin B1\_A12]
- SBU1 [pin A8]
- SBU2 [pin B8]
- SHIELD [pin SH1]
- SHIELD [pin SH4]
- SHIELD [pin SH2]
- SHIELD [pin SH3]
- VBUS\_A [pin A4\_B9]
- VBUS\_B [pin B4\_A9]

### J2 — [Pin Header 01x06 2\.54mm Vertical](https://flux.ai/adrian95/pin-header-01x06-2p54mm-vertical~lzd.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector
- Functional Group: UART Programming

**Pins:**
- Pin\_1 [pin 1]
- Pin\_2 [pin 2]
- Pin\_3 [pin 3]
- Pin\_4 [pin 4]
- Pin\_5 [pin 5]
- Pin\_6 [pin 6]

### J3 — [284391\-4](https://flux.ai/adrian95/284391-4.md)

- Manufacturer Name: TE Connectivity
- Manufacturer Part Number: 284391\-4
- Functional Group: Sensor Connector
- Compliance: Green
- Datasheet URL: https://www\.te\.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=1\-1773458\-1\_EURO\_STYLE\_QRG&DocType=Data%20Sheet&DocLang=English&PartCntxt=284391\-4&DocFormat=pdf
- Part Type: Connector
- Mount: Base
- Symbol Style: parametric\-v1

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### J4 — [Pin Header 01x02 2\.54mm Vertical](https://flux.ai/jharwinbarrozo/generic-pin-header-01x02-2p54mm-vertical~4uy.md)

- Functional Group: RS485
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector

**Pins:**
- P1 [pin 1]
- P2 [pin 2]

### LED1 — [SML\-D13FWT86C](https://flux.ai/jecstronic/sml-d13fwt86c~i2q.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: Indicators
- Manufacturer Name: Rohm Semiconductor
- Manufacturer Part Number: SML\-D13FWT86C
- Part Type: LED
- Datasheet URL: https://fscdn\.rohm\.com/en/products/databook/datasheet/opto/led/chip\_mono/sml\-d13fwt86\(c\)\-e\.pdf

**Pins:**
- A [pin 2]
- K [pin 1]

### LED2 — [SML\-D14U2WT86C](https://flux.ai/jecstronic/sml-d14u2wt86c~zwg.md)

- Part Type: LED
- Datasheet URL: https://fscdn\.rohm\.com/en/products/databook/datasheet/opto/led/chip\_mono/sml\-d14u2wt86\(c\)\-e\.pdf
- Manufacturer Part Number: SML\-D14U2WT86C
- Manufacturer Name: Rohm Semiconductor
- Functional Group: Indicators
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- A [pin 2]
- K [pin 1]

### LED3 — [SML\-D14U2WT86C](https://flux.ai/jecstronic/sml-d14u2wt86c~zwg.md)

- Functional Group: Indicators
- Part Type: LED
- Datasheet URL: https://fscdn\.rohm\.com/en/products/databook/datasheet/opto/led/chip\_mono/sml\-d14u2wt86\(c\)\-e\.pdf
- Manufacturer Part Number: SML\-D14U2WT86C
- Manufacturer Name: Rohm Semiconductor
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- A [pin 2]
- K [pin 1]

### Q1 — [AO3401A](https://flux.ai/jecstronic/ao3401a~9r5.md)

- Functional Group: USB Input
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: AO3401A
- Part Type: Transistor
- Datasheet URL: https://www\.lcsc\.com/datasheet/lcsc\_datasheet\_2007171935\_HUASHUO\-AO3401A\_C700954\.pdf
- Manufacturer Name:  HUASHUO

**Pins:**
- D [pin 3]
- G [pin 1]
- S [pin 2]

### SW1 — [KH\-6X6X5H\-STM](https://flux.ai/lcsc/kh-6x6x5h-stm~12so.md)

- Throw Configuration: SPST
- LCSC Part Number: C2837531
- License: https://creativecommons\.org/licenses/by/4\.0/
- Functional Group: MCU
- Manufacturer Part Number: KH\-6X6X5H\-STM
- Switch Type: Tactile Switch
- Current Rating: 50mA
- Voltage Rating: 12V
- Contact Material: gold\-plated or silver alloy
- Part Type: Tactile Switches
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2837531\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=FlkNBAIDRQULVABfFAVZBgZVFVZYBgZSQ1NeBVIFQlExVlNeR1JcV1VQQ1FWUDsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- JLCPCB Part Class: Extended Part
- Manufacturer Name: kinghelm\(金航标\)
- Package or Case Code: SW\-SMD\_4P\-L6\.0\-W6\.0\-P4\.50\-LS9\.0\-2

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### SW2 — [KH\-6X6X5H\-STM](https://flux.ai/lcsc/kh-6x6x5h-stm~12so.md)

- Throw Configuration: SPST
- LCSC Part Number: C2837531
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: KH\-6X6X5H\-STM
- Functional Group: MCU
- Switch Type: Tactile Switch
- Current Rating: 50mA
- Voltage Rating: 12V
- Contact Material: gold\-plated or silver alloy
- Part Type: Tactile Switches
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2837531\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=FlkNBAIDRQULVABfFAVZBgZVFVZYBgZSQ1NeBVIFQlExVlNeR1JcV1VQQ1FWUDsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- JLCPCB Part Class: Extended Part
- Manufacturer Name: kinghelm\(金航标\)
- Package or Case Code: SW\-SMD\_4P\-L6\.0\-W6\.0\-P4\.50\-LS9\.0\-2

**Pins:**
- 1 [pin 1]
- 2 [pin 2]
- 3 [pin 3]
- 4 [pin 4]

### U1 — [ESP32\-WROOM\-32E\-N4](https://flux.ai/lcsc/esp32-wroom-32e-n4~cokv.md)

- Product Info Url: https://lcsc\.com/product\-detail/WIFI\-Modules\_Espressif\-Systems\-ESP32\-WROOM\-32E\-4MB\_C701341\.html
- Operating Temperature: –40 \~ 85 °C
- Package or Case Code: WIFI\-SMD\_ESP32\-WROOM\-32E
- Operating Voltage: 3\.0 \~ 3\.6 V
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2410301607\_Espressif\-Systems\-ESP32\-WROOM\-32E\-N4\_C701341\.pdf
- Manufacturer Name: ESPRESSIF\(乐鑫\)
- Functional Group: MCU
- Role Details: Main MCU\. PCB antenna at module edge requires keepout: no copper/traces/planes under antenna area on any layer per Espressif WROOM\-32E placement guidance\.
- Frequency: 2412 \~ 2484 MHz
- Manufacturer Part Number: ESP32\-WROOM\-32E\-N4
- LCSC Part Number: C701341
- JLCPCB Part Class: Extended Part
- Part Type: WiFi Modules

**Pins:**
- 3V3 [pin 2]
- EN [pin 3]
- GND [pin 38]
- GND [pin 15]
- GND [pin 39]
- GND [pin 1]
- IO0 [pin 25]
- IO12 [pin 14]
- IO13 [pin 16]
- IO14 [pin 13]
- IO15 [pin 23]
- IO16 [pin 27]
- IO17 [pin 28]
- IO18 [pin 30]
- IO19 [pin 31]
- IO2 [pin 24]
- IO21 [pin 33]
- IO22 [pin 36]
- IO23 [pin 37]
- IO25 [pin 10]
- IO26 [pin 11]
- IO27 [pin 12]
- IO32 [pin 8]
- IO33 [pin 9]
- IO34 [pin 6]
- IO35 [pin 7]
- IO4 [pin 26]
- IO5 [pin 29]
- NC [pin 17]
- NC [pin 32]
- NC [pin 19]
- NC [pin 21]
- NC [pin 20]
- NC [pin 22]
- NC [pin 18]
- RXD0 [pin 34]
- SENSOR\_VN [pin 5]
- SENSOR\_VP [pin 4]
- TXD0 [pin 35]

### U2 — [TPS56339DDC](https://flux.ai/kicad-part-library/tps56339ddc~yca.md)

- Manufacturer Part Number: TPS56339DDC
- Manufacturer Name: Texas Instruments Inc\.
- Datasheet URL: https://www\.ti\.com/lit/ds/symlink/tps56339\.pdf
- Functional Group: Power 3V3 Buck
- Package or Case Code: SOT\-23\-6

**Pins:**
- BOOT [pin 6]
- EN [pin 5]
- FB [pin 4]
- GND [pin 1]
- SW [pin 2]
- VIN [pin 3]

### U3 — [TPS61170QDRVRQ1](https://flux.ai/lcsc/tps61170qdrvrq1~m756.md)

- Functional Group: Power 12V Boost
- Manufacturer Part Number: TPS61170QDRVRQ1
- Product Info Url: https://lcsc\.com/product\-detail/DC\-DC\-Converters\_Texas\-Instruments\_TPS61170QDRVRQ1\_Texas\-Instruments\-TI\-TPS61170QDRVRQ1\_C202235\.html
- JLCPCB Part Class: Extended Part
- LCSC Part Number: C202235
- Part Type: DC\-DC Converters
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2410010332\_Texas\-Instruments\-TPS61170QDRVRQ1\_C202235\.pdf
- Package or Case Code: WSON\-6\_L2\.0\-W2\.0\-P0\.65\-BL\-EP
- Manufacturer Name: TI\(德州仪器\)

**Pins:**
- COMP [pin 2]
- CTRL [pin 5]
- EP [pin 7]
- FB [pin 1]
- GND [pin 3]
- SW [pin 4]
- VIN [pin 6]

### U4 — [MAX3485ESA\+](https://flux.ai/lcsc/max3485esaplus~baoy.md)

- Part Type: Integrated Circuit
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: MAX3485ESA\+
- LCSC Part Number: C1545222
- Package or Case Code: SO\-8\_L4\.9\-W3\.9\-P1\.27\-LS6\.0\-BL
- Datasheet URL: https://www\.analog\.com/media/en/technical\-documentation/data\-sheets/max3483\-max3491\.pdf
- Functional Group: RS485
- Symbol Style: parametric\-v1
- Manufacturer Name: MAXIM\(美信\)

**Pins:**
- \~\{RE\} [pin 2]
- A [pin 6]
- B [pin 7]
- DE [pin 3]
- DI [pin 4]
- GND [pin 5]
- RO [pin 1]
- VCC [pin 8]

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/me\-devin/neckdown\-culling\-retest\~nqn](https://flux.ai/me-devin/neckdown-culling-retest~nqn).*

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*Generated from [https://flux\.ai/me\-devin/neckdown\-culling\-retest\~nqn](https://flux.ai/me-devin/neckdown-culling-retest~nqn)*