VetNode: Cattle Health Monitoring System (LoRa + GSM)

An ESP32-based health monitoring system for livestock. This project uses wearables (Nodes) on cows to track vital signs and a central Gateway to aggregate data and send descriptive SMS alerts.

🚀 Key Features

• Non-blocking Architecture: State-machine driven GSM and sensor handling prevents UI freezing and packet loss.
• Robust LoRa Link: Synchronized parameters (433MHz) with auto-recovery and signal strength monitoring.
• Descriptive Alerts: SMS messages include real-time temperature and heart rate values for immediate diagnosis.
• Power Management: Automated OLED timeout and configurable sleep timers to preserve gateway battery.
• Persistent Config: Change alert thresholds and phone numbers via the on-device menu; settings survive reboots.
• Live Diagnostics: Dashboard includes "Last Seen" tickers, LoRa signal bars, and detailed Serial debugging.

🛠️ Hardware Requirements

• Microcontroller: ESP32-WROOM-32 (Node & Gateway)
• Node Sensors:
  • MAX30102 (Heart Rate & SpO2)
  • DS18B20 (Temperature)
• Communication modules:
  • SX1278 LoRa Module (433MHz)
  • SIM800L GSM Module (Gateway only)
• Timekeeping: DS3231 RTC module (Node)

📌 Pin Mapping (Standardized)

LoRa SX1278 (SPI) - Node & Gateway

Signal	Pin
SCK	18
MISO	19
MOSI	23
SS (CS)	5
RST	14
DIO0	2

Node Sensors & LEDs

Component	Pin
I2C SDA (MAX/RTC)	21
I2C SCL (MAX/RTC)	22
DS18B20 OneWire	15
LED Green	32
LED Red	33

Gateway GSM & UI

Component	Pin
GSM TX	17 (Serial2)
GSM RX	16 (Serial2)
OLED SDA	21
OLED SCL	22
BTN MENU	25
BTN SELECT	26
BUZZER	27

📦 Software Dependencies

Install via Arduino Library Manager:

• RadioLib (v7.6.0+)
• Adafruit SH110X & Adafruit GFX
• DallasTemperature & OneWire
• RTClib & MAX30105
• Preferences (ESP32 Built-in)

📥 Getting Started

1. Setup Node:
   • Open Node/Node.ino.
   • Ensure COW_ID is set correctly.
   • Flash to the wearable ESP32.
2. Setup Gateway:
   • Open Gateway/Gateway.ino.
   • Access the CONFIG menu on-device to set your GSM NUMBER.
   • Adjust SMS INTERVAL and ALERT LIMITS as needed.
3. Powering SIM800L:
   • Crucial: Use a dedicated 5V power source capable of 2A peaks for the SIM800L.

🛰️ System Architecture

Gateway Firmware (Gateway.ino)

• handleGsmState(): Non-blocking state machine managing the SIM800L module boot, text mode set, and SMS transmission.
• queueAlert(const char *reason): Centralized alert handler that validates safety thresholds, manages the SMS cooldown (1-60m), and triggers the buzzer.
• renderDashboard(): Dynamic UI engine that displays real-time cow statistics, LoRa signal bars, and the "Last Seen" ticker.
• scanButtons(): Debounced input handler that manages UI navigation and wakes the OLED display from timeout.
• loadConfig() / saveConfig(): Uses ESP32 Preferences NVS to store user settings (GSM number, limits) across reboots.

Cow Node Firmware (Node.ino)

• readTemperature(): Samples the DS18B20 sensor with signal isolation (disabling LEDs during read) to prevent noise-based glitches.
• checkHeartRateQuick(): Optimized pulse-detection algorithm that processes MAX30102 IR samples in real-time.
• loop() Background Tasks:
  • Transmits a "Heartbeat" (HB) packet every 2 seconds.
  • Monitors for remote "CMD" packets from the Gateway (LED Control/Pings).
  • Handles auto-retry logic for I2C sensors if hardware connection is lost.

⚠️ Safety Thresholds

Default cattle health ranges:

• Temperature: 37.0°C - 39.5°C
• Heart Rate: 50 - 90 BPM
• Alerts are sent immediately on breach, followed by a configurable cooldown (default 5m).

🚀 Deployment Checklist

• Verify 2A power supply for Gateway SIM800L.
• Install all dependencies via Arduino Library Manager.
• Set your phone number in the CONFIG -> GSM NUMBER menu on first boot.
• Ensure the DS18B20 sensor is firmly connected to Node Pin 15.