Five-channel fan controller

A compact 24 V control board developed for independent speed control and operational supervision of five industrial fans.

My role: Hardware and firmware development
Status: Prototype brought up
Platform: STM32F103 · CAN 2.0B
Scope: Architecture to bench testing

Front 3D render of the five-channel fan controller PCB

Overview

Purpose and engineering scope

The public description focuses on system-level design decisions and development work without exposing production files.

The device

The controller drives five 24 V fans as independent channels. Each channel combines PWM speed control with tachometer monitoring, allowing the supervisory system to command airflow and detect missing or abnormal rotation.

Development responsibility

System architecture and interface definition.
Schematic design, component selection and PCB layout.
STM32 firmware for PWM generation, tachometer acquisition and diagnostics.
CAN communication and a UART-based service interface for bench tests.
Prototype bring-up, measurements and fault investigation.

5independent fan channels

24 Vindustrial fan supply

CANsystem communication

STM32real-time control

Architecture

Hardware and firmware blocks

Hardware

An STM32F103 coordinates five PWM outputs and five tachometer inputs. Dedicated MOSFET driver stages switch the fan channels, while the CAN transceiver connects the controller to the host system. A separate UART header supports commissioning and diagnostics.

Firmware

The firmware handles channel commands, duty-cycle updates, tachometer pulse processing, fan-status evaluation and communication. A service mode makes it possible to command each channel independently and inspect measured status during bring-up.

Validation and troubleshooting

Bench work included channel-by-channel functional tests, PWM and tachometer measurements, CAN/UART diagnostics and investigation of irregular fan behaviour. The analysis covered both firmware timing and hardware effects such as signal integrity, pull-up behaviour and unintended current paths through feedback lines.

Disclosure note: exact schematics, PCB source files, production firmware and protocol details are intentionally not published.

Gallery

PCB development views

The gallery shows layout and 3D views of the prototype. Use the arrows, thumbnails or keyboard arrow keys to navigate.

Front 3D render of the assembled fan controller board — Front 3D render of the assembled PCB.

Top copper and component layout view of the fan controller PCB — Top-side PCB layout and routing view.

Bottom copper layout view of the fan controller PCB — Bottom-side copper and routing view.

Rear 3D render of the fan controller board — Rear 3D view with interface and fan-channel markings.

Contact

Need a custom controller?

Contact RK-PRO to discuss hardware architecture, PCB development, firmware, prototype bring-up or design review.

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