In modern automation, flexibility matters. Developers want hardware that can handle real-world input and output signals while remaining open to custom programming, network integration, and smart automation platforms.

Eletechsup ES32D26 is designed for exactly this kind of flexibility. Combining an ESP32 expansion platform with digital I/O, analog signal interfaces, relay outputs, and RS485 communication, it offers a practical foundation for DIY automation, industrial monitoring, and simple PLC-style applications.

What makes the ES32D26 particularly interesting is its potential beyond traditional relay control: developers can build their own applications and explore integrations with popular open-source automation software.

1. One Board, Multiple Industrial I/O Functions

The ES32D26 integrates several types of I/O resources on one expansion board:

• 8 optically isolated digital inputs for monitoring external signals and switches

• 8 relay outputs for controlling compatible electrical loads

• 4 current inputs supporting 0/4–20 mA signals

• 4 voltage inputs supporting 0–5 V or 0–10 V signals

• 2 configurable analog outputs, selectable between voltage and current output modes

• RS485 communication for connecting compatible industrial devices

• An ESP32 expansion slot for programmable wireless and automation applications

The board supports 12 V or 24 V DC power, depending on the selected version. The two analog output channels share their voltage/current selection, so the output mode must be configured according to the hardware settings.

By combining digital and analog signals on one platform, the ES32D26 can help simplify prototyping and reduce the need for multiple separate interface boards.

2. Exploring ESPHome and Home Assistant Integration

Open-source software can make hardware more accessible to developers and system integrators.

The ES32D26 has already attracted interest from developers exploring ESPHome configurations and Home Assistant integration. Eletechsup has also published customer-contributed sample configurations, demonstrating how the board can be adapted for customized automation projects.

With suitable firmware and configuration, potential applications include:

• Wi-Fi-based relay control

• Monitoring voltage and current signals

• Home Assistant automation

• Remote equipment monitoring

• Timed switching and automated sequences

• Custom sensor and actuator integration

These projects illustrate an important advantage of ESP32-based hardware: users are not limited to a single predefined application. They can develop their own logic and connect the board to a broader automation ecosystem.

Actual functionality depends on the firmware, hardware configuration, and compatibility of the selected components.

3. An Open Platform for Custom Automation

The ES32D26 is also listed as supported hardware in the community-developed HypervisionPLC project on GitHub.

HypervisionPLC explores PLC-style programming on ESP32 hardware, including Modbus communication, a Structured Text logic runtime, counters, timers, and a web-based interface. Its repository identifies the ES32D26 as one of its supported hardware platforms.

This creates an interesting development opportunity for engineers who want to experiment with programmable logic without immediately moving to a conventional industrial PLC system.

For example, a developer could explore a project that combines:

• Digital inputs for detecting switches or machine states

• Relay outputs for controlling equipment

• Analog inputs for collecting sensor measurements

• RS485 for communication with compatible devices

• Custom logic for timers, counters, and automation sequences

These are potential project directions rather than a claim that every function is preconfigured or ready to use out of the box.

4. Potential Applications

The combination of ESP32 programmability and multiple I/O types makes the ES32D26 suitable for exploring a variety of applications.

Smart home and building automation

Control compatible lighting, pumps, valves, and other devices while monitoring external signals.

Industrial monitoring

Collect analog measurements and digital status signals, then develop custom monitoring or alerting functions.

Small automation projects

Build relay sequences, timed operations, and simple control logic for prototypes or small machines.

IoT development

Use ESP32-based firmware and compatible network integrations to connect physical I/O with dashboards and automation platforms.

Education and engineering prototyping

Explore embedded programming, Modbus communication, analog signal acquisition, and PLC-style control on a single hardware platform.

As with any development board, suitability for a specific installation depends on electrical ratings, environmental requirements, software implementation, and applicable safety standards.

5. Why Open-Source Examples Matter

For hardware manufacturers, open-source examples provide more than visibility. They can help developers understand how a product might fit into their own projects.

Community repositories and shared configurations can help users:

• Learn from practical integration examples

• Reduce the initial software development effort

• Explore compatibility with existing automation tools

• Adapt hardware to their own requirements

• Share improvements and identify new use cases

The ES32D26's appearance in ESPHome-related work and the HypervisionPLC project demonstrates that developers are exploring its potential in more than one software ecosystem.

Eletechsup welcomes developers, engineers, and automation enthusiasts to explore the hardware, develop their own applications, and share useful examples with the community.

Conclusion: Flexible Hardware for Creative Automation

The Eletechsup ES32D26 brings together an ESP32 expansion platform, digital and analog I/O, relay control, and RS485 communication in one versatile board.

Whether you are experimenting with Home Assistant, developing an ESPHome-based project, exploring PLC-style logic, or building a custom industrial monitoring system, the ES32D26 provides a flexible starting point for your next idea.

Eletechsup — Practical I/O Hardware for Industrial Automation, IoT and Custom Development.

Product page: https://eletechsup.com/products/es32d26-2ao-8ai-8di-8do-esp32-wifi-network-relay-board-4-20ma-0-10v-digital-analog-input-output-module-for-smart-switch-iot-simple-plc

Developer resources:

• ESPHome example: https://github.com/alray31/ES32D26-ESPHome

• HypervisionPLC: https://github.com/Jangreenlarsen/HypervisionPLC

• Eletechsup sample code from customers: https://eletechsup.com/blogs/news/es32d26-sample-code-from-italy-customer