EarthSentinel — Wenner 4-Probe Soil Resistivity Tester

About this project

EarthSentinel is an ESP32-based Wenner 4-probe soil resistivity tester built for the electrical earthing design workflow taught in IS 3043 and IEEE 80. A GPIO output injects a brief DC current pulse into the outer probe pair (C1–C2) through a 150Ω safety resistor; the ESP32's ADC simultaneously reads the inner probe voltage (P1 at GPIO34) and the shunt voltage (P2/C2 junction at GPIO35 via a 10Ω shunt). Internal resistance is computed as R = (V_P1 − V_C2) × R_shunt / V_C2, then converted to soil resistivity ρ = 2πaR where a is the configurable probe spacing. Results are classified EXCELLENT / GOOD / FAIR / HIGH-R per IS 3043 earthing guidelines. A 2.4-inch ILI9341 TFT colour display shows all metrics; an ESP32 WiFi web server hosts a dashboard where the probe spacing can be adjusted in centimetres.

What you get

• Complete, commented source code
• Full components list with quantities
• Pin-by-pin wiring guide and connection table
• Step-by-step upload and testing guide
• Project report (.docx, IEEE style)
• Presentation slides (.pptx)