Supported Targets	ESP32-S3

Mainly 3d printed rain sensor with integration to HomeAutomation project

Rain Sensor Project

Hardware:

• Based on a rainsensor hardware from AliExpress
• Due to much noise when the rocker hits the base I made some modifications

Features

• Rocker arm mechanism for precise rain detection.
• Modular electronics with adjustable thresholds and low-power operation.
• LoRa/Wi-Fi/MQTT integration for seamless data transmission.
• Dynamic parameter adjustments based on rainfall intensity.

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Electronics Overview

• Axle & Suspension

  • New axle mounting with TPU suspension.
  • Redesigned base with TPU buffers for the rocker arm.

• Sensing & Signal Processing

  • Hall sensor SS49E (replaces reed contact).
  • LM393P dual-stage comparator circuit:
    • Adjustable threshold.
    • Second stage with feedback to prevent oscillations.
    • 3.3V logic-compatible digital output for ESP32-S3.

• Mechanical Adjustments

  • Dual-plate base leveling system with knurled nuts.
  • Wedge plate to compensate for garage roof slope.
  • Cable clamp integrated into the base plate.

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Software Overview

Core Logic

• Ultra-Low Power (ULP) Co-Processor:

  • Pulse counting handled by the ESP32-S3 ULP for energy efficiency.
  • Main processor sleeps until:
    • A predefined pulse count (Ti) is reached.
    • A time interval (Tm) expires for rainfall calculation.

• Rainfall Calculation:

  • Volume computed using:
    • Bucket volume of the rocker arm.
    • Pulse count and time interval (Tm).

• Dynamic Transmission:

  • Data sent at interval Tt, adjusted based on rainfall intensity.
  • If no rain:
    • Main processor wakes after interval Tks to report status/battery.
    • Remains ready for parameter updates.

Configuration

• Time intervals (Ti, Tm, Tt, Tks) and thresholds configurable via LoRa.

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Power Management

• 3.3V LiPo-based power supply optimized for long-term operation.
• ESP32-S3 ULP ensures minimal power consumption during idle states.

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Data Transmission

• LoRa for long-range, low-power communication.
• LoRa-to-Wi-Fi Bridge:
  • Integrates with home automation systems.
  • Converts LoRa payloads to MQTT topics.

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Integration & Visualization

• Home Automation:
  • MQTT integration via Node-RED for automation workflows.
• Data Pipeline:
  • Node-RED → InfluxDB → Grafana dashboards.

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Setup & Parameters

Key parameters (adjust via LoRa/MQTT):

Ti  = Wake-up pulse count  
Tm  = Rainfall calculation interval  
Tt  = Dynamic data transmission interval  
Tks = Status check interval (no-rain condition)