Building a Smart Home Control Center from Scratch: My Practical Experience with Siemens LOGO!

Hello everyone, let me introduce myself briefly

I am an engineer with over ten years of experience in the field of automation control, and I enjoy tinkering with various smart home devices. Today, I want to share how to use the Siemens LOGO! small PLC to build your own smart home control center. I remember when I first started with LOGO!, I took quite a few detours, and I hope my experiences can help those interested in smart homes avoid some of those pitfalls.

Whether you are an electrical engineering professional or a pure DIY enthusiast, this article can help you create a practical and affordable smart home control system. After all, spending a few thousand yuan to build a professional-grade control center is much more economical than commercial solutions that often exceed ten thousand, right?

Hardware Preparation: These are the essentials you need

First, we need to prepare the following hardware:

• Siemens LOGO! Basic Model 8.3 (recommended: 12/24RCE)
• Expansion modules (choose digital/analog input/output modules as needed)
• Power supply module (24V DC regulated power supply)
• Network cable (for connecting to the home network)
• Various sensors (temperature and humidity, light, door/window magnetic, human detection, etc.)
• Actuating devices (relays, light controllers, motors, etc.)

Tip: If your budget is limited, you can start by purchasing the basic model and necessary sensors, and then gradually expand later. I initially set up the basic system to control a few lights and curtains, and then slowly added other functions.

System Design Approach: Plan Before You Start

Before you start, I strongly recommend that you plan the functions you need. From my personal experience, it’s best not to be greedy at the beginning; solidifying the basic functions is the key.

The core functions of my smart home control include:

1. Intelligent lighting control (timing, scenes, remote)
2. Curtain automation (light sensing, timing, remote)
3. Temperature and humidity monitoring with air conditioning linkage
4. Simple security monitoring (door/window status, abnormal alarms)

When designing the system, my suggestion is to adopt a modular approach, dividing functions into several independent subsystems, which will make maintenance and expansion much easier later on. I once crammed all functions into one program block, and debugging and modifying it later was a nightmare.

LOGO! Software Configuration: The Easiest Setup

After installing the LOGO! Soft Comfort software (the latest version is V8.3), we can start programming. I personally prefer using FBD (Function Block Diagram) programming because it is intuitive and easy to understand.

Basic Configuration Steps:

1. Create a new project and select the correct LOGO! model
2. Set the IP address and network parameters (it is recommended to set a fixed IP)
3. Create basic function blocks (timers, counters, logic gates, etc.)

My Experience: Network configuration is a common issue for many friends. Be sure to ensure that the LOGO! and your computer are on the same subnet; otherwise, they will not communicate. I got stuck here for a long time during my first configuration, only to find out later that the IP address was set incorrectly.

Core Program Implementation: These Functional Modules are Very Useful

Here are a few functional modules that I frequently use:

Lighting Control Module

stylus copy

// Simplified lighting control logic
I1 (human detection) ---> AND1 ---> Q1 (living room light)
I2 (light sensor) ---> |
B1 (time control) ---> |

This simple logic implements the function of “the light turns on when someone is present at night.” It uses the light sensor to determine if it is night, and the human detector to check for presence; the light will only turn on when both conditions are met.

Curtain Control Module

My curtain control uses a dual-trigger mechanism of light and time. In the morning, when the light reaches a certain intensity, the curtains automatically open; in the evening, when the light is below a threshold or the set time is reached, the curtains automatically close.

Tip: When controlling the curtain motor, be careful with the interlocking of forward and reverse rotation. I once burned out the motor due to a logic issue in the program that sent both forward and reverse signals at the same time; that was a painful lesson!

Remote Control: Control Your Home Anytime, Anywhere

The LOGO! 8.3 has a built-in web server, allowing us to access and control it directly through a web page. The steps are as follows:

1. Enable the web server in LOGO! Soft Comfort
2. Design a custom display interface
3. Access the LOGO! IP address through a browser

If you want to access it from outside, I recommend configuring port forwarding on your home router or using a VPN. For security reasons, it is not advisable to expose the LOGO! directly on the public internet.

Practical Advice: I created a dedicated shortcut on my phone to access my home control system anytime. Sometimes I forget to turn off the lights when I go out, or I want to close the curtains while lying in bed; I can operate it directly from my phone, which is very convenient.

Practical Case: My Home’s Smart Scene

Let me share a practical scene I use at home—”Movie Mode”:

When I press a specific button in the living room or trigger “Movie Mode” through my phone, LOGO! will perform the following actions:

• The main light in the living room automatically dims to 30%
• The TV backlight turns on
• The curtains automatically close
• The air conditioning temperature adjusts to a comfortable level

This scene is very simple to implement with LOGO!; it only requires a few function blocks. The best part is that all device interactions are done locally, without relying on cloud services, ensuring fast response times and immunity to network fluctuations.

Common Issues and Solutions

During my usage, I encountered these common issues, which I would like to share:

1. LOGO! Cannot Communicate with the Computer

   • Check the network connection and IP address configuration
   • Confirm whether the firewall is blocking communication

2. Program Runs Unstable

   • Avoid overly complex logic nesting
   • Add appropriate delays to prevent false triggers

3. Sensor Data Inaccurate

   • Check the installation position and connections of the sensors
   • Add filtering function blocks to handle signal jitter

Words of Experience: Keeping good logs and handling exceptions is very important! I once had a sensor failure that caused the system to restart repeatedly; later, I added exception handling logic, which greatly improved system stability.

In Conclusion: The Joy of Smart Homes

After all this time spent on smart homes, my biggest realization is that true intelligence is not about how many high-tech devices you have, but whether the system can truly understand and adapt to your living habits.

Siemens LOGO!, although an industrial product, has irreplaceable advantages in home scenarios: it is stable, reliable, powerful, and highly expandable. Most importantly, it allows us to customize a smart home system that truly fits our needs.

I hope my sharing is helpful to everyone. If you have any questions or good ideas, feel free to discuss. After all, the journey of smart homes becomes more interesting the further you go!