IoT Greenhouse Climate Monitor

Overview

Monitor environmental conditions in your greenhouse, grow room, or any space using a BME280 sensor connected to a Raspberry Pi. Get real-time readings via chat and set up automated alerts for out-of-range conditions. What it does:

Read temperature, humidity, and pressure
Get climate updates via chat
Automated alerts for threshold violations
Historical data tracking

Hardware: Raspberry Pi 4/5, BME280 sensor (I²C) APIs used: Custom Edge API + Lua Data API (for history)

Architecture

User Chat → Lua Agent → ReadClimateTool → Edge API → BME280 → Environmental Data

Complete Implementation

Edge API on Raspberry Pi

Setup (one-time)

# Install OS packages
sudo apt update
sudo apt install -y python3-pip python3-venv i2c-tools

# Enable I2C interface
sudo raspi-config nonint do_i2c 0
# Or use raspi-config TUI: Interface Options → I2C → Enable

# Create project folder
mkdir -p ~/iot-edge && cd ~/iot-edge
python3 -m venv .venv
source .venv/bin/activate

# Install dependencies
pip install flask adafruit-blinka adafruit-circuitpython-bme280

Verify I2C Connection

# Check if BME280 is detected (should show 0x76 or 0x77)
i2cdetect -y 1

Edge API Code

Update edge_api.py (or add to existing):

from flask import Flask, request, jsonify
from functools import wraps
import os, time

try:
    import board, busio
    from adafruit_bme280 import basic as adafruit_bme280
    
    _i2c = busio.I2C(board.SCL, board.SDA)
    _bme280 = adafruit_bme280.Adafruit_BME280_I2C(_i2c)
except Exception as e:
    _bme280 = None
    print(f"BME280 not available: {e}")

app = Flask(__name__)
API_KEY = os.environ.get("EDGE_API_KEY", "changeme")

def require_key(fn):
    @wraps(fn)
    def wrapper(*args, **kwargs):
        if request.headers.get("X-API-Key") != API_KEY:
            return jsonify({"error": "unauthorized"}), 401
        return fn(*args, **kwargs)
    return wrapper

@app.get("/health")
def health():
    return {"ok": True, "ts": int(time.time())}

@app.get("/sensors/env")
@require_key
def sensors_env():
    if not _bme280:
        return jsonify({"error": "BME280 not available"}), 400
    
    return {
        "temperature_c": round(_bme280.temperature, 2),
        "temperature_f": round(_bme280.temperature * 9/5 + 32, 2),
        "humidity": round(_bme280.humidity, 1),
        "pressure_hpa": round(_bme280.pressure, 1),
        "timestamp": int(time.time())
    }

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5001)

Run Edge API

export EDGE_API_KEY="supersecret"
python edge_api.py

Test Edge API

curl -H "X-API-Key: supersecret" http://raspberrypi.local:5001/sensors/env

Lua Agent Implementation

src/tools/ReadClimateTool.ts

import { LuaTool, Data, env } from 'lua-cli';
import { z } from 'zod';

export default class ReadClimateTool implements LuaTool {
  name = "read_climate";
  description = "Read temperature, humidity, and pressure from BME280 sensor";
  
  inputSchema = z.object({
    storeHistory: z.boolean().default(true).describe("Save reading to history")
  });

  async execute(input: z.infer<typeof this.inputSchema>) {
    const base = env('PI_BASE_URL');
    const key = env('PI_API_KEY');
    
    if (!base || !key) {
      throw new Error('PI_BASE_URL or PI_API_KEY not configured');
    }

    const res = await fetch(`${base}/sensors/env`, {
      headers: { 'X-API-Key': key }
    });
    
    if (!res.ok) {
      throw new Error(`Edge API error: ${res.status} ${await res.text()}`);
    }
    
    const data = await res.json();
    
    // Store in history if requested
    if (input.storeHistory) {
      await Data.create('climate_readings', {
        temperature_c: data.temperature_c,
        temperature_f: data.temperature_f,
        humidity: data.humidity,
        pressure_hpa: data.pressure_hpa,
        timestamp: new Date().toISOString()
      }, `climate ${data.temperature_c}C ${data.humidity}% ${data.pressure_hpa}hPa`);
    }
    
    return {
      temperature: `${data.temperature_c}°C (${data.temperature_f}°F)`,
      humidity: `${data.humidity}%`,
      pressure: `${data.pressure_hpa} hPa`,
      timestamp: new Date(data.timestamp * 1000).toLocaleString(),
      status: this.evaluateConditions(data)
    };
  }
  
  private evaluateConditions(data: any): string {
    const alerts = [];
    
    if (data.temperature_c > 30) alerts.push("⚠️ High temperature");
    if (data.temperature_c < 15) alerts.push("❄️ Low temperature");
    if (data.humidity > 80) alerts.push("💧 High humidity");
    if (data.humidity < 30) alerts.push("🏜️ Low humidity");
    
    return alerts.length > 0 
      ? alerts.join(', ')
      : '✅ All conditions normal';
  }
}

src/index.ts

import { LuaAgent, LuaSkill, LuaJob } from 'lua-cli';
import ReadClimateTool from './tools/ReadClimateTool';

// Climate monitoring skill
const climateSkill = new LuaSkill({
  name: "greenhouse-climate",
  description: "Monitor greenhouse environmental conditions",
  context: `
    This skill monitors temperature, humidity, and pressure via BME280 sensor.
    
    - read_climate: Get current environmental readings
      Use when user asks about temperature, humidity, pressure, or conditions
      
    Always mention if conditions are outside normal range.
    Suggest actions for out-of-range conditions.
  `,
  tools: [new ReadClimateTool()]
});

// Hourly climate check job
const hourlyClimateCheckJob = new LuaJob({
  name: 'hourly-climate-check',
  description: 'Check climate conditions every hour and alert if out of range',
  schedule: {
    type: 'interval',
    intervalSeconds: 3600  // Every hour
  },
  execute: async (job) => {
    const tool = new ReadClimateTool();
    const reading = await tool.execute({ storeHistory: true });
    
    // Alert if conditions are abnormal
    if (reading.status !== '✅ All conditions normal') {
      const user = await job.user();
      await user.send([{
        type: 'text',
        text: `🌡️ Climate Alert:\n\n${reading.temperature}\n${reading.humidity}\n${reading.pressure}\n\n${reading.status}`
      }]);
    }
  }
});

// Configure agent
export const agent = new LuaAgent({
  name: "greenhouse-monitor",
  
  persona: `You are a greenhouse climate monitoring assistant.
  
Your role:
- Monitor temperature, humidity, and pressure
- Alert when conditions are out of range
- Provide climate recommendations
- Track environmental history

Communication style:
- Clear and data-driven
- Proactive with alerts
- Helpful with recommendations

Climate knowledge:
- Ideal temp: 18-28°C (64-82°F)
- Ideal humidity: 50-70%
- Normal pressure: 980-1020 hPa

Recommendations:
- High temp: Increase ventilation
- Low temp: Close vents, add heat
- High humidity: Increase air circulation
- Low humidity: Add water trays or misting

When to alert:
- Temperature outside 15-30°C
- Humidity outside 30-80%
- Rapid changes (>5°C/hour)`,

  
  skills: [climateSkill],
  jobs: [hourlyClimateCheckJob]
});

Uses LuaAgent with scheduled jobs for hourly climate monitoring and automated alerts.

Environment Setup

# .env
PI_BASE_URL=http://raspberrypi.local:5001
PI_API_KEY=supersecret

Wiring BME280

I²C Connection:

Raspberry Pi          BME280
-----------          -------
3.3V        ────────> VIN
GND         ────────> GND
GPIO 2 (SDA)────────> SDA
GPIO 3 (SCL)────────> SCL

I²C Address: BME280 typically uses 0x76 or 0x77. The Adafruit library auto-detects the address.

Testing

# Test tool directly
lua test
# Select: read_climate

# Test conversationally
lua chat
# You: "What's the temperature and humidity?"
# You: "Check the greenhouse conditions"
# You: "Is it too hot in there?"

Key Features

Real-Time Monitoring

Instant environmental readings via chat

Automated Alerts

Hourly checks with out-of-range notifications

Historical Data

Store readings in Lua Data for trend analysis

Smart Recommendations

AI suggests actions based on conditions

Customization Ideas

Add Alert Thresholds

inputSchema = z.object({
  storeHistory: z.boolean().default(true),
  alertIfTempAbove: z.number().optional(),
  alertIfHumidityAbove: z.number().optional()
});

Daily Summary Report

const dailySummaryJob = new LuaJob({
  name: 'daily-climate-summary',
  schedule: {
    type: 'cron',
    pattern: '0 8 * * *'  // 8 AM daily
  },
  execute: async (job) => {
    // Get last 24 hours of readings
    const readings = await Data.get('climate_readings', 24);
    
    const avgTemp = readings.reduce((sum, r) => sum + r.data.temperature_c, 0) / readings.length;
    const avgHumidity = readings.reduce((sum, r) => sum + r.data.humidity, 0) / readings.length;
    
    const user = await job.user();
    await user.send([{
      type: 'text',
      text: `📊 24-Hour Climate Summary:\n\nAvg Temp: ${avgTemp.toFixed(1)}°C\nAvg Humidity: ${avgHumidity.toFixed(1)}%\nReadings: ${readings.length}`
    }]);
  }
});

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IoT Greenhouse Climate Monitor

Overview

Architecture

Complete Implementation

Edge API on Raspberry Pi

Setup (one-time)

Verify I2C Connection

Edge API Code

Run Edge API

Test Edge API

Lua Agent Implementation

src/tools/ReadClimateTool.ts

src/index.ts

Environment Setup

Wiring BME280

Testing

Key Features

Real-Time Monitoring

Automated Alerts

Historical Data

Smart Recommendations

Customization Ideas

Add Alert Thresholds

Daily Summary Report

Next IoT Demo

Security Camera Snapshot

​Overview

​Architecture

​Complete Implementation

​Edge API on Raspberry Pi

​Setup (one-time)

​Verify I2C Connection

​Edge API Code

​Run Edge API

​Test Edge API

​Lua Agent Implementation

​src/tools/ReadClimateTool.ts

​src/index.ts

​Environment Setup

​Wiring BME280

​Testing

​Key Features

Real-Time Monitoring

Automated Alerts

Historical Data

Smart Recommendations

​Customization Ideas

​Add Alert Thresholds

​Daily Summary Report

​Next IoT Demo

Security Camera Snapshot

Overview

Architecture

Complete Implementation

Edge API on Raspberry Pi

Setup (one-time)

Verify I2C Connection

Edge API Code

Run Edge API

Test Edge API

Lua Agent Implementation

src/tools/ReadClimateTool.ts

src/index.ts

Environment Setup

Wiring BME280

Testing

Key Features

Customization Ideas

Add Alert Thresholds

Daily Summary Report

Next IoT Demo