Predictive Maintenance

This repository contains Arduino sketches and supporting files for a predictive maintenance platform that reads multiple sensors and (optionally) transmits data via LoRa. The original project combined multiple sensors in a single sketch; this repo splits each sensor/module into standalone sketches in sensor_modules/ so you can test and deploy them independently.

Repository layout

• sensor_modules/ — Individual Arduino sketches for each sensor/module (PT100 MAX31865, analog pressure, MQ135 gas, energy meter, vibration sensor, LoRa comm, etc.).
• final_code/ — The original merged sketch (kept for reference).
• communication_modules/ — Example LoRa communication sketches/modules.
• datasheets/, images/ — Supporting documents and wiring diagrams.

Quick start

1. Open the sketch you want in the Arduino IDE (for example sensor_modules/temperature_sensor.ino).
2. Make sure the required libraries are installed (see "Dependencies" below).
3. Configure wiring and pins in the sketch if your hardware differs from the defaults.
4. Upload the sketch and open the Serial Monitor at 9600 baud to view sensor output.

Dependencies

• Adafruit MAX31865 library (for PT100): Adafruit_MAX31865
• ModbusMaster library (for RS485 Modbus devices): ModbusMaster
• SoftwareSerial (built into Arduino core)

Install missing libraries using the Arduino Library Manager or via PlatformIO.

Hardware & Sensors

Use this section to list the exact hardware you're using for this deployment. Copy/paste and fill the items below so it's easier to reproduce or document later.

• Arduino board: Arduino Nano Every
• LoRa module: RYLR993 Lite
• Temperature Sensor: PT100 RTD + MAX31865 module
• Pressure Sensor: PYROTECH Piezoresistive Pressure Sensor
• Gas Sensor: MQ135
• Energy Sensor: Multispan MFM 13-M1 with in-built RS485
• Vibration Sensor: Wit WVB01485
• RS485 driver module: MAX485
• Power supply: Three Phase (415V), Single Phase (210V), DC (12-24V)
• Any level shifters or gates: Resistors (220 ohm, 250 ohm)

Wiring reference (common/default wiring used in sketches)

• LoRa Module (serial-AT style): TX -> Board RX (Serial1), RX -> Board TX (Serial1). Configure baud in lora_communication.ino.
• MAX31865 (PT100): CS -> D10, DI -> D11, DO -> D12, CLK -> D13 (temperature_sensor.ino).
• Analog Pressure Sensor: OUT -> A0 (see pressure_sensor.ino).
• MQ135 Gas Sensor: AOUT -> A1 (see gas_sensor.ino). Set RL_VALUE in code to match module.
• MAX485 RS485 adapter: RO -> D2 (Software RX), DI -> D3 (Software TX), DE & RE -> D4 (direction control). A/B -> RS485 bus.

Sensor sketches and how to use them

• sensor_modules/temperature_sensor.ino — Reads PT100 temperature via Adafruit MAX31865. Includes fault detection and RTD resistance output.
• sensor_modules/pressure_sensor.ino — Reads analog pressure on A0 and maps ADC to pressure (placeholder mapping 0–10 bar). Calibrate for your sensor.
• sensor_modules/gas_sensor.ino — Reads MQ135 on A1. Prints ADC, voltage and computed Rs (kΩ). Optional auto-calibration to determine R0 in clean air.
• sensor_modules/energy_sensor.ino (or power_meter_modbus.ino if present) — Uses SoftwareSerial ModbusMaster to query the MFM 13-M1 power meter registers. Check modbus register addresses and slave ID in the sketch.
• sensor_modules/vibration_sensor.ino — Reads vibration sensor registers over Modbus (slave ID 0x50 by default), applies scaling multipliers for accel/speed/displacement, and prints values.
• communication_modules/lora_communication.ino or sensor_modules/lora_comm_from_unified.ino — Helper functions to send AT commands and transmit payloads via LoRa (AT-mode modules). Update serial pins/baud as required.

Calibration notes

• PT100: tune RREF and RNOMINAL to match your PT100 and reference resistor. Use known temperature points to verify.
• Pressure sensor: perform a two-point calibration using known pressures (0 and full scale) and compute a linear mapping.
• MQ135: requires sensor-specific curve to convert Rs/R0 to PPM for specific gases. Common approach: measure R0 in clean air, then use curve parameters from MQ135 datasheet or community libraries. Consider storing R0 in EEPROM after calibration.
• Modbus devices: verify register addresses and byte order. The ModbusMaster library used assumes register order used in the original sketch; adjust if you see incorrect values.