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ENVIRONMENTAL IOT // FDC2214 CAPACITIVE SOIL MOISTURE

Pure Soil Sensor — Differential Capacitive Soil Moisture & BLE Probe

The Pure Soil Sensor is a three-zone wireless capacitive moisture probe that measures air, mid-soil, and deep-soil hydration. The probe pairs a Texas Instruments FDC2214 differential capacitance-to-digital converter with coplanar PCB electrodes and plugs directly into an nRF52 PUREmodules CoreModule to stream telemetry over Bluetooth Low Energy and MQTT.

Start Similar Custom Project → All Reference Projects 28-Year Portfolio Quick Startup Guide ↗ Github site ↗

Architecture & Technical Specifications

Hardware Architecture & Features

  • Three-segment coplanar differential capacitive sensing zones for air, mid-soil, and deep-soil hydration.
  • Texas Instruments FDC2214 multi-channel capacitance-to-digital converter with EMI filtering and common-mode choke.
  • Solderless 62-mil card-edge plug-and-play connection to the nRF52 PUREmodules CoreModule.

Firmware, Software & Integration

  • Open-source nRF52 BLE firmware exposing a custom GATT service with 3 read characteristics and 1 configuration characteristic.
  • Open-source Android application with live time-series plotting, threshold indicators, and MQTT broker publishing.

Hardware Photos & Figures (11)

Pure Soil Sensor hardware figure 1
Pure Soil Sensor hardware figure 1
Pure Soil Sensor hardware figure 2
Pure Soil Sensor hardware figure 2
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Capture.JPG
Pure Soil Sensor hardware figure 4
Pure Soil Sensor hardware figure 4
Pure Soil Sensor hardware figure 5
Pure Soil Sensor hardware figure 5
Pure Soil Sensor hardware figure 6
Pure Soil Sensor hardware figure 6
Pure Soil Sensor hardware figure 7
Pure Soil Sensor hardware figure 7
Pure Soil Sensor hardware figure 8
Pure Soil Sensor hardware figure 8
Pure Soil Sensor hardware figure 9
Pure Soil Sensor hardware figure 9
Pure Soil Sensor hardware figure 10
Pure Soil Sensor hardware figure 10
Pure Soil Sensor hardware figure 11
Pure Soil Sensor hardware figure 11

Datasheets, Source Code & Reference Links

Quick Startup Guide EXTERNAL ↗ Github site EXTERNAL ↗ Android App Source Code EXTERNAL ↗ Pure Engineering LLC Home Page EXTERNAL ↗ PUREmodules RELATED → PUREmodules Quick Start Guide RELATED → Modular Sensor Architecture RELATED →