Industrial RS-485/Modbus Raspberry Pi HAT Works with OpenPLC, Supports 7V-32V DC Input

Key Takeaways

• Supports 7‑32 V DC input, powers Pi and HAT.
• Uses Pi hardware UART, compatible with all 40‑pin models.
• OpenPLC‑optimized for low‑latency ladder logic.
• Built‑in TVS diodes protect against ESD and spikes.
• Priced $9 on Tindie, shipping $7‑15 worldwide.

Summary

EngineElectronicAccessories released an Industrial RS‑485/Modbus HAT for Raspberry Pi that integrates a protected RS‑485 transceiver and a wide‑range DC input. The board draws power directly from 7 V‑32 V rails, feeding both the HAT and the Pi via an onboard buck converter. It connects through the Pi’s hardware UART, includes diagnostic LEDs, and is tuned for OpenPLC’s low‑latency ladder‑logic execution. The HAT is priced at $9 on Tindie, with shipping ranging from $7.4 to $15.

Pulse Analysis

The new RS‑485/Modbus HAT addresses a long‑standing gap in the Raspberry Pi ecosystem: a dedicated, industrial‑grade serial interface that also handles power conversion. Traditional Pi‑based gateways often require separate power supplies and external RS‑485 adapters, adding cost and wiring complexity. By integrating a Mini560 DC‑DC buck converter capable of accepting 7 V‑32 V, the HAT lets engineers feed a single 24 V rail—common in factories—directly into the board, eliminating the need for extra power modules and reducing cabinet space.

Beyond power consolidation, the HAT’s hardware UART connection offers deterministic timing essential for PLC workloads. OpenPLC developers benefit from the board’s pinout and timing alignment, which minimizes latency when executing ladder‑logic programs. Diagnostic Tx/Rx LEDs provide immediate visual feedback, simplifying troubleshooting in noisy industrial environments. Although the RS‑485 transceiver lacks galvanic isolation, the inclusion of TVS diodes mitigates voltage spikes and ESD, delivering a reasonable protection level for cost‑sensitive deployments.

Pricing at $9 positions the HAT as an attractive entry point for small‑scale automation, energy‑monitoring, and smart‑metering projects. Its compatibility with all 40‑pin Raspberry Pi models—from Pi Zero to Pi 5—ensures broad adoption across legacy and new installations. As edge computing gains traction, devices that combine power, communication, and open‑source PLC support will become pivotal in building scalable, low‑cost industrial IoT solutions.