STMicroelectronics STEVAL-IHM037V1

Overview

STEVAL-IHM037V1 from STMicroelectronics is a ceiling fan remote control demonstration board built around the STM8S003F3 microcontroller (receiver) and STM8L101F2 (IR remote), featuring triac-based AC motor speed control via firing angle adjustment, 180–250 VAC operation, and RC5 infrared protocol support for wireless speed regulation in residential ceiling fan systems.

For engineers reviewing the STEVAL-IHM037V1 datasheet, STEVAL-IHM037V1 pinout, STEVAL-IHM037V1 application, or STEVAL-IHM037V1 equivalent, this board serves as a validated reference design for AC induction motor speed control using low-cost capacitive power supply, IR remote interface, and pushbutton manual override - critical for rapid prototyping of energy-efficient fan control solutions.

Technical Context

The board implements zero-crossing synchronized triac triggering using the STM8S003F3's timer and GPIO to adjust firing angle across the 50/60 Hz AC line cycle, enabling precise 3-speed fan control. The IR receiver decodes RC5 commands, while the STM8L101F2 in the remote operates from a CR2032 battery with ultra-low-power standby current.

Capacitive dropper power supply delivers regulated 5 V to the receiver MCU without a transformer, meeting cost and size constraints for retrofit fan controllers. Two tactile pushbuttons provide local speed increment/decrement independent of IR signal reception.

Key Specifications

Availability

STEVAL-IHM037V1 is available at Aetrix Electronics and suitable for ceiling fan control development, residential HVAC subsystem integration, and IR-enabled AC motor drive prototyping requiring stable component supply and reference design validation.

Supply support for STEVAL-IHM037V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series - purpose-built demonstration platforms that validate real-world use cases for ST microcontrollers and power components, specifically targeting appliance control and energy-efficient motor drive reference designs.

FAQ

What is the primary function of the STEVAL-IHM037V1?

The STEVAL-IHM037V1 is a complete reference design for wireless and manual speed control of single-phase induction motor–based ceiling fans. It replaces traditional mechanical regulators with an STM8-driven triac firing-angle controller, accepting RC5 infrared commands and local pushbutton inputs to adjust motor speed across three discrete levels.

Does the board include both transmitter and receiver hardware?

Yes - the STEVAL-IHM037V1 kit includes two physically separate units: a mains-connected receiver board with STM8S003F3 and triac driver circuitry, and a battery-powered IR remote containing the STM8L101F2 MCU and RC5 encoder. Both are fully assembled and tested per ST's DocID023317 Rev 2.

Can the triac control be adapted for other AC loads?

The T435x triac and associated snubber and zero-crossing detection circuitry are rated for resistive and inductive loads up to 435 V peak and 4 A RMS. While optimized for ceiling fan motors, the design can be reconfigured for other single-phase AC loads such as exhaust fans, pumps, or lighting ballasts - subject to thermal derating and EMI compliance verification.

Is firmware source code provided with the board?

Yes - ST provides full IAR Embedded Workbench project files, C source code, and application notes (AN4219) covering triac timing calibration, RC5 decoding, and pushbutton debouncing logic. All firmware is open for modification and reuse under ST's standard license terms for evaluation hardware.