# ESP32 WiFi Water Flow Meter

## Description

USB\-C powered ESP32 WiFi water flow meter interface for a 3/4 inch PVC ultrasonic RS485 flow sensor, including 12V sensor power, 3\.3V logic power, protection, status LEDs, and programming/reset support\.

## Project Details

- **Owner:** yousifq
- **Created:** 8/15/2024
- **Last Updated:** 6/3/2026
- **Visibility:** Public

## Key Components

### D1 — [USBLC6\-2SC6](https://flux.ai/lcsc/usblc6-2sc6~2e9x.md)

- JLCPCB Part Class: Extended Part
- Manufacturer Name: UMW\(友台半导体\)
- Symbol Style: parametric\-v1
- Breakdown Voltage: 6V
- Manufacturer Part Number: USBLC6\-2SC6
- Operating Temperature: \-55°C \~ 125°C \(TJ\)
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2687116\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=FlkNBAIDRQULVABfFAVZBgZVFVZYBgZSQ1NeBVIFQlExVlNRTlhdUVdURFlXXzsOAxUeFF5JWBYZEEoKFBINSQcJGk4dAgUUFAk%3D
- Maximum Clamping Voltage: 17V
- Part Type: ESD Protection Devices
- Role: ESD Protection
- Package or Case Code: SOT\-23\-6\_L2\.9\-W1\.6\-P0\.95\-LS2\.8\-BL
- Role Details: Low capacitance dual\-line USB ESD protection
- Peak Pulse Current: 5A
- Power: 150W
- LCSC Part Number: C2687116

**Pins:**
- GND [pin 2]
- I/O1 [pin 1]
- I/O1 [pin 6]
- I/O2 [pin 3]
- I/O2 [pin 4]
- VBUS [pin 5]

### D2 — [SRDA3\.3\-6\.TBT](https://flux.ai/baueralex174/srda3p3-6ptbt~pu.md)

- Package or Case Code: SOIC127P600X170\-9N
- Manufacturer Part Number: SRDA3\.3\-6\.TBT
- Part Type: SRDA3\.3\-6\.TBT
- Compliance: Pb\-Free,Halogen Free,RoHS/WEEE Compliant
- Manufacturer Name: Semtech Corporation
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.semtech\.com/uploads/documents/SRDA3\.3\-6\.pdf
- Role: ESD Protection
- Role Details: Protects external RS485 A/B lines at sensor connector

**Pins:**
- GND [pin 8]
- I/O 1 [pin 1]
- I/O 2 [pin 2]
- I/O 3 [pin 4]
- I/O 4 [pin 5]
- I/O 5 [pin 6]
- I/O 6 [pin 7]
- VREF [pin 3]

### D3 — [SS14](https://flux.ai/jecstronic/ss14~ri4.md)

- Role: Boost Rectifier
- Manufacturer Name: Slkor\(SLKORMICRO Elec\.\)
- Datasheet URL: https://datasheet\.lcsc\.com/lcsc/1912111437\_Slkor\-SLKORMICRO\-Elec\-\-SS14\_C444721\.pdf
- Part Type: Diode
- Role Details: MT3608 12V boost diode
- Manufacturer Part Number: SS14
- License: https://creativecommons\.org/licenses/by/4\.0/

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

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

- Role: Protection
- Manufacturer Name: Littelfuse Inc\.
- Role Details: 1\.1A hold PTC for \~0\.86A estimated peak input current
- 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)

- Role: Power Input
- 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/
- Role Details: USB\-C sink input with CC pull\-downs, 5V only no PD
- Manufacturer Name: GCT
- 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 — [DB127V\-5\.08\-2P\-GN\-S](https://flux.ai/cherepanyadima/db127v-5p08-2p-gn-s~ic.md)

- Role: Field Connector
- Role Details: External ultrasonic flow sensor connection
- Manufacturer Part Number: DB127V\-5\.08\-2P\-GN\-S
- Part Type: Connector
- Datasheet URL: https://www\.lcsc\.com/datasheet/C3018698\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=ElhbUlFSRlUNBF0CQlQIBQBUFFILBFEAQVVWUgZWE1gxVlNRQVVdVFRSQ1daVDsOAxUeFF5JWBYZEEoBGA4JCwFIFA4DSA%3D%3D
- Manufacturer Name: DORABO

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

### J3 — [DB127V\-5\.08\-2P\-GN\-S](https://flux.ai/cherepanyadima/db127v-5p08-2p-gn-s~ic.md)

- Role: Field Connector
- Manufacturer Part Number: DB127V\-5\.08\-2P\-GN\-S
- Part Type: Connector
- Datasheet URL: https://www\.lcsc\.com/datasheet/C3018698\.pdf?spm=wm\.sxq\.inf\.ggs&lcsc\_vid=ElhbUlFSRlUNBF0CQlQIBQBUFFILBFEAQVVWUgZWE1gxVlNRQVVdVFRSQ1daVDsOAxUeFF5JWBYZEEoBGA4JCwFIFA4DSA%3D%3D
- Role Details: External ultrasonic flow sensor connection
- Manufacturer Name: DORABO

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

### J4 — [Pin Header 01x06 2\.54mm PROGRAMMING CONNECTOR](https://flux.ai/zalak201285/pin-header-01x06-2p54mm-programming-connector~ji.md)

- Role Details: 3\.3V UART programming/debug with EN and BOOT control pins
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector
- Role: Programming Header

**Pins:**
- JTCK [pin 2]
- JTDI [pin 1]
- JTDO [pin 3]
- JTMS [pin 4]
- NJTRST [pin 5]
- RESET [pin 6]

### LED1 — [BZ\-C0603\-G3\-F1](https://flux.ai/lcsc/bz-c0603-g3-f1~v6dg.md)

- JLCPCB Part Class: Extended Part
- Package or Case Code: LED0603\-R\-RD\_GREEN
- Part Type: Light Emitting Diodes \(LED\)
- Manufacturer Name: baizou\(百洲\)
- LCSC Part Number: C2833058
- Role: Status Indicator
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2833058\.pdf
- Role Details: Power, WiFi, and flow activity indication
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BZ\-C0603\-G3\-F1

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

### LED2 — [BZ\-C0603\-G3\-F1](https://flux.ai/lcsc/bz-c0603-g3-f1~v6dg.md)

- JLCPCB Part Class: Extended Part
- Package or Case Code: LED0603\-R\-RD\_GREEN
- Part Type: Light Emitting Diodes \(LED\)
- Manufacturer Name: baizou\(百洲\)
- LCSC Part Number: C2833058
- Role Details: Power, WiFi, and flow activity indication
- Role: Status Indicator
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2833058\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BZ\-C0603\-G3\-F1

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

### LED3 — [BZ\-C0603\-G3\-F1](https://flux.ai/lcsc/bz-c0603-g3-f1~v6dg.md)

- JLCPCB Part Class: Extended Part
- Package or Case Code: LED0603\-R\-RD\_GREEN
- Part Type: Light Emitting Diodes \(LED\)
- Manufacturer Name: baizou\(百洲\)
- LCSC Part Number: C2833058
- Role Details: Power, WiFi, and flow activity indication
- Datasheet URL: https://www\.lcsc\.com/datasheet/C2833058\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BZ\-C0603\-G3\-F1
- Role: Status Indicator

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

### SW1 — [TS\-1088\-AR02016](https://flux.ai/lcsc/ts-1088-ar02016~e3n1.md)

- Role Details: Momentary switch to ground for reset/boot
- Manufacturer Name: XUNPU\(讯普\)
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2409302330\_XUNPU\-TS\-1088\-AR02016\_C720477\.pdf
- 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
- Role: User Control
- LCSC Part Number: C720477
- Part Type: Tactile Switches
- Package or Case Code: SW\-SMD\_L3\.9\-W3\.0\-P4\.45

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

### SW2 — [TS\-1088\-AR02016](https://flux.ai/lcsc/ts-1088-ar02016~e3n1.md)

- Role Details: Momentary switch to ground for reset/boot
- Manufacturer Name: XUNPU\(讯普\)
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2409302330\_XUNPU\-TS\-1088\-AR02016\_C720477\.pdf
- JLCPCB Part Class: Extended Part
- Role: User Control
- 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
- Part Type: Tactile Switches
- Package or Case Code: SW\-SMD\_L3\.9\-W3\.0\-P4\.45

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

### U1 — [ESP32\-WROOM\-32E\-N16](https://flux.ai/jecstronic/esp32-wroom-32e-n16~wqb.md)

- Manufacturer Part Number: ESP32\-WROOM\-32E\-N16
- License: https://creativecommons\.org/licenses/by/4\.0/
- Datasheet URL: https://www\.espressif\.com/sites/default/files/documentation/esp32\-wroom\-32e\_esp32\-wroom\-32ue\_datasheet\_en\.pdf
- Role: WiFi MCU
- Role Details: ESP32 module, UART to RS485 transceiver, status GPIOs, boot/reset support
- Part Type: Module
- Manufacturer Name: Espressif Systems

**Pins:**
- 3V3 [pin 2]
- EN [pin 3]
- GND [pin 47]
- GND [pin 43]
- GND [pin 40]
- GND [pin 44]
- GND [pin 46]
- GND [pin 45]
- GND [pin 1]
- GND [pin 38]
- GND [pin 39]
- GND [pin 42]
- GND [pin 41]
- GND [pin 15]
- 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 21]
- NC [pin 32]
- NC [pin 18]
- NC [pin 20]
- NC [pin 22]
- NC [pin 19]
- NC [pin 17]
- RXD0 [pin 34]
- SENSOR\_VN [pin 5]
- SENSOR\_VP [pin 4]
- TXD0 [pin 35]

### U2 — [AMS1117\-3\.3](https://flux.ai/vasy_skral/ams1117-33~34.md)

- Role: Voltage Regulator
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: AMS 
- Part Type: Integrated Circuit
- Symbol Style: Parametric
- Role Details: 5V to 3\.3V logic rail sized for ESP32 WiFi peaks; requires copper for heat spreading
- Manufacturer Part Number: AMS1117\-3\.3
- Datasheet URL: http://www\.advanced\-monolithic\.com/pdf/ds1117\.pdf

**Pins:**
- GND [pin 1]
- TAB\(VOUT\) [pin 4]
- VIN [pin 3]
- VOUT [pin 2]

### U3 — [MT3608 \- 4414693](https://flux.ai/kicad-part-library/mt3608-4414693~ao3.md)

- Package or Case Code: SOT\-23\-6
- Role: Boost Regulator
- Manufacturer Part Number: MT3608
- Datasheet URL: https://www\.olimex\.com/Products/Breadboarding/BB\-PWR\-3608/resources/MT3608\.pdf
- Role Details: 5V to 12V sensor rail, assumed 100mA peak sensor load

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

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

- Part Type: Integrated Circuit
- Role Details: Half\-duplex RS485 interface for ultrasonic flow sensor
- 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
- Role: RS485 Transceiver
- Datasheet URL: https://www\.analog\.com/media/en/technical\-documentation/data\-sheets/max3483\-max3491\.pdf
- 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/yousifq/esp32\-wifi\-water\-flow\-meter\~3c](https://flux.ai/yousifq/esp32-wifi-water-flow-meter~3c).*

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*Generated from [https://flux\.ai/yousifq/esp32\-wifi\-water\-flow\-meter\~3c](https://flux.ai/yousifq/esp32-wifi-water-flow-meter~3c)*