The Evolution of Programming in HMI Displays for Mobile Machinery

August 30, 2023

HMI Display programming method history
Human-Machine Interface (HMI) displays serve as the control centers of various heavy machinery, including agricultural vehicles, construction equipment, and municipal vehicles such as recycling trucks. With advancements in technology, the programming languages that fuel these interfaces have also evolved. This article provides an in-depth exploration of the past, present, and potential future of HMI programming in these critical industries.

Then: Anchored by CODESYS

CODESYS: The Industry-Specific Solution

Industrial Standard

CODESYS had the advantage of being an industry-specific solution tailored for PLC (Programmable Logic Controller) and HMI applications in mobile machinery and heavy equipment.

Ease of Use

Engineers didn’t have to be deeply involved in programming to use CODESYS. It featured drag-and-drop components and easy-to-use interface elements, making it accessible even for those without extensive coding knowledge.

Plug-and-Play Functionality

CODESYS also offered pre-built libraries and modules designed to meet the specific needs of various industrial sectors, further simplifying its usage.

Now: The Diversity of C, C++, and CODESYS

C Programming: A Tried-and-True Choice

Resource Efficiency

In the early years, hardware resources were limited. C became a favorite because it was highly efficient, ensuring that machines ran smoothly without consuming too many computational resources.


C remains relevant, particularly in MM-IoT (Mobile Machine Internet of Things) applications. It can interface with a variety of hardware components, an important trait given the increasing interconnectivity of modern machinery.

Resource Efficiency

In the early years, hardware resources were limited. C became a favorite because it was highly efficient, ensuring that machines ran smoothly without consuming too many computational resources.

Direct Hardware Access

One of the strengths of C is the ability to manipulate hardware directly. This proved vital in old machinery, where customized solutions were often needed for specialized sensors and actuators.

Community and Documentation

C has an expansive range of libraries and a large, well-documented community of users, which made problem-solving much more straightforward in the later stages of development for HMIs.

C++: The Newcomer Gaining Ground

Object-Oriented Features

C++ allows for object-oriented programming, introducing a higher level of code organization, modularity, and reusability.

Rich Library Support

Like C, C++ has a rich standard library but offers more in terms of functionality and data manipulation capabilities.

CODESYS: A Declining Titan?

Cost Concerns

The primary reason CODESYS is seeing less use is the cost of licenses. These are becoming increasingly burdensome, especially for companies that manage a large fleet of vehicles or equipment.

Limited Flexibility

As machinery becomes more complex, CODESYS is sometimes seen as less flexible compared to more versatile languages like C and C++.

Next: The Rise of C++, Java, and Python

C++: Scalability for Tomorrow


As machinery becomes smarter and more complex, C++’s object-oriented architecture will continue to make it a preferred choice for scalable solutions.

Java: The Networked Future

Platform Independence

One of Java’s strongest traits is its write-once, run-anywhere capability. This becomes important as we see a growing trend towards the networking of mobile machinery and heavy equipment.

Python: The Language of Innovation

Simplicity and Accessibility

Python is known for its ease of use, and this will likely attract new generations of programmers to the field of HMI development.

AI Prowess

Python is increasingly becoming the language of choice for AI applications, which are anticipated to become a significant part of future mobile machinery.

The Role of AI in Future Mobile Machinery

As machinery becomes smarter, AI is going to play an increasingly important role in its operation. Here’s how:

Predictive Maintenance

Imagine a piece of construction machinery that uses AI to predict when it will require maintenance. Not only would this minimize downtime, but it could also extend the lifespan of the machine.

Automated Decision-Making

A self-driving tractor could analyze various environmental parameters in real-time to optimize planting or harvesting strategies without human intervention.

Safety Enhancements

AI systems in municipal vehicles like recycling trucks could identify unsafe conditions – such as a person getting too close to the vehicle while it is working and is out of view of the operator – and being able to automatically take corrective action faster than a human could.

Resource Optimization

In agricultural settings, AI could control irrigation systems, nutrient distribution, and more, all optimized for current soil and weather conditions.

Data-Driven Insights

Advanced analytics made possible by AI can provide operators with valuable insights into machine performance, operational efficiency, and other key metrics. Python, given its leading role in AI and machine learning, will likely be at the forefront of these advances, ensuring that future HMI displays are not just control panels but intelligent interfaces capable of autonomous decision-making and real-time analytics.


The evolving programming landscape for the mobile machine markets is constantly adapting to the technological needs of the field. From the straightforward and reliable solutions offered by C and CODESYS to the increasing versatility of languages like C++, Java, and Python, the future of more intelligent, interconnected, and autonomous systems looks full of innovative possibilities. With the integration of AI, the future holds the promise of machinery that is not just more efficient but also smarter and more adaptive to the complexities of modern market demands.

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About STW Technic

STW Technic is an innovative leader in the design, manufacture, and implementation of electronic solutions for mobile machines and off-highway vehicles. We partner with machine manufacturers, system integrators, and distributors to provide engineered and highly reliable connectivity, automation, and power management solutions to truly empower their mobile machines. We offer the latest in Mobile Machine IoT hardware and software solutions, such as our market-leading remote asset management platform – Reach. We also provide solutions such as openSYDE – our systems configuration tool – to support the entire lifecycle of your machine.