# Soil Moisture Probe ## Description 150 mm x 15 mm 2-layer soil moisture probe using an external 3.3 V supply, FDC1004 capacitance sensor, DS18B20 temperature sensor, top-half component placement, and a bottom-half exposed interdigitated sensing electrode region on both copper layers with 1 mm trace/space for JLCPCB 0.8 mm fabrication. ## Project Details - **Owner:** jwacrelink01 - **Created:** 4/20/2026 - **Last Updated:** 4/24/2026 - **Visibility:** Public ## Key Components ### J1 — [B5B-PH-SM4-TB](https://www.flux.ai/adrian95/b5b-ph-sm4-tb~d0z.md) - Package: JST PH 2.00mm SMD 5-pin - Connector Positions: 5 - Role: Connector - Role Details: External interface carrying 3.3V, GND, SDA, SCL, and 1WIRE - Connector Type: Wire To Board - Part Type: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Connector Pitch: 2.0mm - Datasheet URL: https://www.jst-mfg.com/product/pdf/eng/ePH.pdf - Manufacturer Name: JST - Manufacturer Part Number: B5B-PH-SM4-TB **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - SHIELD [pin SH2] - SHIELD [pin SH1] ### U1 — [FDC1004DGSR](https://www.flux.ai/lcsc/fdc1004dgsr~p5ae.md) - Manufacturer Name: Texas Instruments - Package or Case Code: MSOP-10 - Role: Capacitance Sensor - Role Details: Measures capacitance from PCB soil sensing electrodes via I2C interface - LCSC Part Number: C2865994 - JLCPCB Part Class: Extended Part - Manufacturer Part Number: FDC1004DGSR - Package: MSOP-10 **Pins:** - CIN1 [pin 2] - CIN2 [pin 3] - CIN3 [pin 4] - CIN4 [pin 5] - GND [pin 7] - SCL [pin 9] - SDA [pin 10] - SHLD1 [pin 1] - SHLD2 [pin 6] - VDD [pin 8] ### U2 — [DS18B20U](https://www.flux.ai/lcsc/ds18b20u~z01d.md) - Part Type: Temperature Sensors - Supply Voltage: 2.5~5.5V - Role Details: 1-Wire digital temperature sensor for soil temperature measurement - Package or Case Code: MSOP-8_L3.0-W3.0-P0.65-LS4.9-BL - Standby Current: 750nA - Manufacturer Name: UMW - Package: MSOP-8 - JLCPCB Part Class: Extended Part - Manufacturer Part Number: DS18B20U - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2311091737_UMW-Youtai-Semiconductor-Co---Ltd--DS18B20U_C695836.pdf - Product Info Url: https://lcsc.com/product-detail/Temperature-Sensors_UMW-Youtai-Semiconductor-Co-Ltd-DS18B20U_C695836.html - LCSC Part Number: C695836 - Role: Temperature Sensor - Operating Temperature: -55~+125℃ **Pins:** - DQ [pin 1] - GND [pin 4] - NC [pin 2] - NC [pin 3] - NC [pin 6] - NC [pin 7] - NC [pin 5] - VDD [pin 8] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/jwacrelink01/soil-moisture-probe~qz](https://www.flux.ai/jwacrelink01/soil-moisture-probe~qz).* --- *Generated from [https://www.flux.ai/jwacrelink01/soil-moisture-probe~qz](https://www.flux.ai/jwacrelink01/soil-moisture-probe~qz)*