STM32 Data Acquisition and MQTT Integration | Obeita
This configuration is proposed for assessment. Confirm interfaces, components and performance for your specific project.
Collect instrument data over RS232 or RS485 and publish it to an MQTT broker through an STM32F407-based acquisition board. Ethernet serves a local network, while an EC200M cellular module is the development path for installations without a wired uplink.
From instrument frames to MQTT fields
The collection task needs more than serial forwarding: it must associate each measurement with a device, unit and collection time. We define frame decoding or register reads, scaling and error handling before mapping the result into MQTT topics and payload fields. The exact sensor protocol is selected per instrument; the presence of RS485 does not establish Modbus compatibility.
Ethernet and cellular deployment
Ethernet is suitable for cabinet or workshop networks. An EC200M modem can serve isolated monitoring points after checking the modem variant and local carrier support. Reconnection, authentication and handling of unsent measurements belong in the application design; offline storage is added only when a retention size and replay policy have been agreed.
Monitoring applications and service evidence
Environmental monitoring, irrigation and remote equipment supervision are distinct applications of the same acquisition chain. A useful pilot records raw frames, decoded values, MQTT messages and timestamps side by side. This allows a customer to verify unit conversion, reporting intervals and what happens when the network is deliberately disconnected.
Proposed design configuration
These are configuration inputs for development; the final assembly, firmware and acceptance tests define the delivered specification.
| Item | Configuration |
|---|---|
| Controller | STM32F407 platform |
| Instrument interfaces | RS232 and RS485 |
| Local networking | Ethernet |
| Cellular direction | EC200M; module variant to match deployment |
| Server protocol | MQTT; topics and payload agreed per project |
| Application examples | Environment, agriculture and remote equipment monitoring |
Project questions
Does MQTT support mean compatibility with any cloud?
The broker connection is only one layer. Authentication, topic permissions, field names, units and command responses must match the customer platform.
What is needed to verify measurement accuracy end to end?
Use a known input or instrument reading and compare the raw frame, decoded value and published payload under the same test condition.
Plan this project
Send one representative instrument protocol and the required MQTT payload, including units and reporting interval.