UM1546 Datasheet, PDF (1/17 Pages) STMicroelectronics – STEVAL-IHM037V1 remote fan speed controller

UM1546
User manual
STEVAL-IHM037V1 remote fan speed controller
Introduction
The remote fan speed controller is a single channel TRIAC based solution meant to replace
the existing fan speed controllers and provide the IR remote control feature. It is designed to
fit easily inside an enclosure with the dimensions of a single-switch module.
A non-isolated capacitive power supply is used to power the microcontroller and the IR
sensor. The TSOP38438 IR sensor is used to demodulate the 38 kHz IR signal from the IR
transmitter and decoded by the STM8S003 value line microcontroller to perform the various
control functions. IR communication is based on the RC5 protocol standard. A TRIAC is
used as the control element to regulate the power going into the fan by varying its firing
angle for different speed settings. The speed settings can be changed by using the onboard
tactile switches or by using the IR remote controller.
The STM8S003F3 value line 8-bit microcontroller, with its internal data EEPROM, hardware
timers and external interrupts on GPIOs, makes an efficient implementation of the
application possible while keeping the size, cost and external component count to a
minimum.
Figure 1. Remote fan speed controller board STEVAL-IHM037V1
This document explains the different parts of the application.
The key features of the application are:
■ Fan speed control using SW1, SW2 keys or IR remote
■ Compact and cost effective capacitive power supply
■ Example firmware based on RC5 protocol. Can also work with NEC and other IR protocols
■ Low cost solution. Can be used for light dimmer applications with software modifications.
September 2012
Doc ID 023229 Rev 1
1/17
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