GUIDE5 min readUpdated Jun 2026

Raspberry Pi IoT gateway

Bridge brownfield Modbus/serial gear to MQTT and the cloud — securely, on a board that costs a fraction of an industrial gateway appliance.

SHORT ANSWER

A Raspberry Pi makes an excellent IIoT gateway: it reads brownfield equipment over Modbus RTU/TCP, OPC-UA or serial, normalizes the data, and republishes it to MQTT or a cloud platform over a secure uplink. With TLS, a signed read-only image and network segmentation, it's a defensible OT-to-cloud bridge at a fraction of a commercial gateway's price.

Modbus/OPC-UA/MQTT
protocols bridged
TLS
encrypted uplink
Wi-Fi/Eth/LTE
uplink options

01What a gateway does

It sits between the OT network and the cloud: polling field devices, buffering during outages, transforming data, and publishing upstream. The Pi's Linux stack makes protocol coverage and buffering straightforward.

02Doing it securely

Segment the gateway from the control network, run a signed read-only OS, use TLS and per-device tokens, and ship updates over signed OTA. A patchable, observable gateway is more defensible than an unmanaged appliance.

Common questions

The ones we're asked on every first call.

When hardened — secure boot, read-only rootfs, TLS, segmentation — yes, and arguably more so than an unpatchable appliance, because you can actually observe and update it.

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