Introduction: Build a Smart Temperature Monitor in 5 Minutes (No Coding Required!)

By
About: With Grablo, Anyone can create amazing IoT projects quickly and easily, without writing a single line of code.

Introduction

Traditional IoT projects require hours of programming, library hunting, and debugging. What if you could just think "when temperature gets high, turn on LED and Play voice" and arrange visual blocks to make it happen?

This tutorial shows how Grablo transforms complex IoT development into simple visual logic. We'll build a complete temperature monitoring system in 5 minutes using visual blocks instead of code.


What You'll Build

A complete smart temperature monitoring system with:

  1. Real-time web dashboard showing temperature and humidity
  2. Voice alerts when temperature exceeds your threshold
  3. LED visual indicator for warnings
  4. Smart scheduling (alerts only during work hours)
  5. Automatic recovery notifications

Supplies

Components:

  1. Raspberry Pi 0-4
  2. DHT11 temperature/humidity sensor
  3. LED + 220Ω resistor
  4. Breadboard and jumper wires
  5. Speaker or headphones


Wiring:

  1. DHT11: Data pin → GPIO 23
  2. LED: Anode → 220Ω resistor → GPIO 25
  3. Audio: Speakers → Raspberry Pi audio jack

Step 1: Quick Start

  1. Install software:Download and install Grablo software on your controller hardware
  2. Set up hardware: Connect DHT11 sensor and LED according to circuit diagram
  3. Get this project from Project Link
  4. Connect your controller: In your project, go to "Connect Controller" and enter IP address
  5. Upload audio files: Edit each "Play Media" action, upload the corresponding WAV files (Temperature is high for Control 2, Temperature is normal for Control 3)
  6. Hit RUN! Launch your smart monitoring system

💡 Want to build it yourself? Skip to Step 2 and follow the tutorial


Step 2: Create Project

  1. Go to https://app.grablo.co
  2. Click "Create Project"
  3. Give your project a name

Step 3: Create Dashboard

Create a new dashboard. Add two gauge widgets and connect each to their respective variables:

  1. Temperature Gauge: Connect to temperature variable (Celsius)
  2. Humidity Gauge: Connect to humidity variable (Percentage)

Creating widgets takes just a few clicks, and you can customize the layout with simple drag-and-drop positioning.

Step 4: Build Logic - Control1: Continuous Data Reading

Create new logic and add a control to continuously read temperature and humidity from the DHT11 sensor.

  1. Condition: Always (runs continuously in background)
  2. Action: Read DHT11 sensor from GPIO 23 and store the readings in temperature and humidity variables

Step 5: Build Logic - Control2: High Temperature Alert System

Create a new control that triggers temperature alerts during work hours with the following conditions and actions

  1. Condition 1: Temperature exceeds 30°C (triggers only when temperature first crosses this threshold)
  2. Condition 2: Current time is between 9:00 AM and 5:00 PM (alerts only during work hours)
  3. Action 1: Play voice message "Temperature is high" through speakers
  4. Action 2: Turn on LED connected to GPIO 25 as visual warning

Step 6: Build Logic - Control3: Temperature Recovery Notification

Create a new control that clears temperature alerts when conditions return to normal

  1. Condition: Temperature drops below 28°C (triggers only when temperature first falls below this threshold)
  2. Action 1: Play voice message "Temperature is normal" through speakers
  3. Action 2: Turn off LED connected to GPIO 25 to clear visual warning

Step 7: Launch Your Project

That's It - You're Done!

Congratulations! You've just built a complete smart temperature monitoring system using only 3 simple controls and zero lines of code. This is the power of visual programming with Grablo - focus on creativity and problem-solving instead of wrestling with syntax and debugging code.


Run Your Project

  1. Install software:Download and install Grablo software on your controller hardware
  2. Set up hardware: Connect DHT11 sensor and LED according to circuit diagram
  3. Connect your controller: In your project, go to "Connect Controller" and enter IP address
  4. Upload audio files: Edit each "Play Media" action, upload the corresponding WAV files (Temperature is high for Control 2, Temperature is normal for Control 3)
  5. Hit RUN! Launch your smart monitoring system

Step 8: Video Tutorial

Watch the complete build process in action! This 5-minute video demonstrates every step we covered above - from creating the dashboard to setting up logic controls and launching your smart temperature monitoring system.


Step 9: What's Next?

Expand Your Project

Add more functionality with additional blocks:

  1. Email alerts for critical temperatures (>35°C)
  2. Data logging every 5 minutes for historical analysis
  3. Automatic cooling with relay-controlled fans
  4. Multiple sensors for different rooms or zones


Resources

  1. Official Website:https://grablo.co
  2. Get started:https://app.grablo.co
  3. Documentation:https://doc.grablo.co
  4. Support:support@grablo.co